Home heating automation

Blisterman · 24-09-2020 3:35pm

Getting a central heating system installed on a new build, and I was wondering what types of controls I should be looking for.
I like the idea of having app control, and some kind of room by room control.
What I don't want is to be reliant on a single smart thermostat company having to keep their app updated. Ideally, I'd be using some well established standard that's not tied into one manufacturer or app developer. Sort of like how a bluetooth speaker can be used by any phone with Bluetooth, whereas Sonas requires a specific app.
Does such a thing exist?

iba · 24-09-2020 4:57pm

deezell wrote: »

Just one end, youll only fit one TRV on each rad, the lockshield valve at t'other end is left on and open.

That valve body in the link is 1/2" compression both sides, which your rotary valves appear to be, so if the compression nuts' threads are a match, then it could be an easy swap, re-using the existing nuts already retained on the pipe riser and the rad spigot. Experience tells me even then the thread depth and pipe insert distance can differ, meaning the new body may not seal even if the nut thread gauge is the same, neccitating the removal of the old compression rings from the rad and riser in order to use the new body's nuts. Tedious and tricky for a DIYer.

As regards the body type, that one is a standard M30 thread by 1.5mm depth. Most manual or smart TRVs will fit straight on retrained by the TRV screw ring. However, the Chinese TRVs you are contemplating seem to be manufactured with Danfoss RA clamp on fittings. You would require Danfoss RA valve bodies for a direct fit, such as these.

While it is possibly to adapt these valve bodies to take M30 x 1.5 TRV heads, I'm not certain if you can get the reverse adaptor, RA TRV heads to the common M30 threaded valve body, so if you buy these heads you will need these valve bodies.
Apart from the cost and difficulty of obtaining and fitting these RA bodies, (they dont have a pipe compression fitting, just a f/m 1/2" pipe thread, requiring a brass adaptor, and your rad spigots will need removing), your'e making your TRV bodies off standard for most other TRV heads, requiring plastic head adaptors if you were to later fit Tado or Wiser or other M30 x 1.5 heads. That would look really ugly, with an M30 TRV to an RA adaptor to a RA valve body to a 1/2" gb-to-compression adaptor to your rising pipe.
There must be plenty of low cost TRVs with the M30 fitting, I'd avoid the ones you're considering which are likely manufactured as an electronic upgrade for existing RA bodied Danfoss installations.
Here's a link to Tuya M30 equipped Zigbee TRVs, this is what you want, they'll fit straight to those inexpensive M30 replacement valve bodies.
https://www.aliexpress.com/i/4001039187695.html

Hi Deezel,

Thank you so much for your extremely detailed information. I've read it twice and my brain is fried.

but if I understand everything correctly, and I'm not sure that I do, first I have to change the valves to this:

https://www.danfoss.com/en/products/radiator-and-room-thermostats/dhs/radiator-thermostats/radiator-valves/

and which cost 40 pound sterling on Amazon:

https://www.amazon.co.uk/Danfoss-Radiator-fittings-adjusting-013G0013/dp/B00BLMMTB4/ref=sr_1_8?dchild=1&keywords=danfoss+ra&qid=1600962630&s=diy&sr=1-8

and then I can attach the Tuya ones:

https://www.aliexpress.com/item/4001065031604.html?spm=a2g0o.productlist.0.0.16767772log5K7&s=p&ad_pvid=202009240846469967407176864000000601208_1&algo_pvid=6df519f3-30e2-47b1-82f3-c1bbf0b1345d&algo_expid=6df519f3-30e2-47b1-82f3-c1bbf0b1345d-0&btsid=0bb0624016009624064623562ea108&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

And that's only if I can actually do it as you said it is difficlt for a DIYer (and I count myself as a good DIYer but this might be a step too far).

If my undertstanding is right and those valves do cost 40 pound sterling each, I might just replace all my radiators as they are close on 20 years old now anyway and could do with an upgrade.

Thanks again for your help and indepth knowledge and advice

Regards

deezell · 24-09-2020 5:44pm

Blisterman wrote: »

Getting a central heating system installed on a new build, and I was wondering what types of controls I should be looking for.
I like the idea of having app control, and some kind of room by room control.
What I don't want is to be reliant on a single smart thermostat company having to keep their app updated. Ideally, I'd be using some well established standard that's not tied into one manufacturer or app developer. Sort of like how a bluetooth speaker can be used by any phone with Bluetooth, whereas Sonas requires a specific app.
Does such a thing exist?

What you're looking for is a stat whose API is addressed directly by third party apps, and whose function is independent of an internet connection, i.e, will continue to work if your internet is down, both manually and by direct address from your other smart home interfaces across your internal network. Nest is internet independent in the first instance, and should work internally from your app if you're Wi-Fi is up, though I might be wrong about the latter. Afaik Apple Homekit can connect to device's at local level. I Think more recent versions of Tado are homekit compatible, but Tados own app requires Internet connection to see the stat, and the earlier stats also needs this to function, even manually. As for the other leading brands, I think some are standalone devices also, with the internet and a Wi-Fi connection to their hub or bridge required to enable external app access obviously, and possibly home access. Others might like to comment on this.
As the chain of connection is not always clear, whither via a brand vendor's own server, or directly to the stat by a smart home interface such as Google home or Amazon Alexa, when you use any of these physical devices, or the apps such as SmartThings, or IFTTT, to make changes to your stat settings, you can never tell if the stat vendor (say, Nest or Hive or Tado), needs to be still in business for your hardware to continue to function in the future. Google owns Nest, so I can't see that brand being left without connection, and it's capable of working manually without Wi-Fi, let alone external internet. There have been a few smart devices which have died when their progenitors ceased trading, but that's life in a way, like trying to get spares for a Sanyo microwave or a Rover car.

deezell · 24-09-2020 7:26pm

iba wrote: »

Hi Deezel,

Thank you so much for your extremely detailed information. I've read it twice and my brain is fried.

but if I understand everything correctly, and I'm not sure that I do, first I have to change the valves to this.....

........And that's only if I can actually do it as you said it is difficlt for a DIYer (and I count myself as a good DIYer but this might be a step too far).

If my undertstanding is right and those valves do cost 40 pound sterling each, I might just replace all my radiators as they are close on 20 years old now anyway and could do with an upgrade.

Thanks again for your help and indepth knowledge and advice

Regards

You will only require those valves IF you buy the Tuya TRVs that are designed to clamp to Danfoss RA valve bodies. I don't advise that. What I do advise is to buy Tuya or other brand TRVs that have M30 x 1.5 threaded fittings, then change one valve in each rad to the inexpensive M30 valve body, as little as a fiver each from Stevenson plumbing in Bangor Co. Down. These valves may be a very simple swap for your current rotary type, as both use compression nut and ring on the rad spigot and the riser pipe. Drain, loosen both nuts, pull back old valve from the rad then up from the riser, and if the nut threads match the M30 trv valve bodies, you can just insert them between the old nuts using a bit of PTFE tape. A little more work if you need to use the new valve nuts, ring and rad spigot.
With the Danfoss RA valves you have A lot more fitting.
Here's another link to Tuya zigbee TRV head with the M30 1.5 screw thread fitting to the valve body.
https://m.aliexpress.com/item/4001245603510.html

Just get these, unless you've already got the RA bodied ones?

iba · 24-09-2020 10:54pm

deezell wrote: »

You will only require those valves IF you buy the Tuya TRVs that are designed to clamp to Danfoss RA valve bodies. I don't advise that. What I do advise is to buy Tuya or other brand TRVs that have M30 x 1.5 threaded fittings, then change one valve in each rad to the inexpensive M30 valve body, as little as a fiver each from Stevenson plumbing in Bangor Co. Down. These valves may be a very simple swap for your current rotary type, as both use compression nut and ring on the rad spigot and the riser pipe. Drain, loosen both nuts, pull back old valve from the rad then up from the riser, and if the nut threads match the M30 trv valve bodies, you can just insert them between the old nuts using a bit of PTFE tape. A little more work if you need to use the new valve nuts, ring and rad spigot.
With the Danfoss RA valves you have A lot more fitting.
Here's another link to Tuya zigbee TRV head with the M30 1.5 screw thread fitting to the valve body.
https://m.aliexpress.com/item/4001245603510.html

Just get these, unless you've already got the RA bodied ones?

Hi,

Thanks again.

No I haven't bought anything yet.

Is this the correct 30m valve body that I need:

https://www.stevensonplumbing.co.uk/myson-trv2way-valve-body.html

Thanks

deezell · 25-09-2020 7:58am

iba wrote: »

Hi,

Thanks again.

No I haven't bought anything yet.

Is this the correct 30m valve body that I need:

https://www.stevensonplumbing.co.uk/myson-trv2way-valve-body.html

Thanks

Yes. Start with these. Then virtually any TRV you buy will fit without adaptors.

If you want to replace your rads with new one, you can put these at both ends, the second one acting as the manual valve as the little plastic cap in the picture rotates on the thread to push the pin closed if required to trim the radiator flow and balance the system response. You remove this cap to fit a TRV head. Depending on how old your radiators are, you may not be able to get exact panel size replacements, sizes have changed since the 80's-90's, so the newer sizes will be a bit longer or shorter, requiring extending or cranking of the riser pipes. Heres one on mine I had to do to fit a new twin panel rad replacing a late 80's original. Note the new TRV body from Stevensons.

Grant Stevens · 25-09-2020 9:42pm

Hi, I'd like to ask a question if I may. I have an oil boiler based heating system with 14 radiators. 1995 build so no zones and no smart controls. Just an on/off/clock timer switch.

I'm looking to install the Honeywell Home evo system with the HR92 TRV on each radiator. I have contacted a plumber as he will have to change the valves on all the radiators so that the trv heads will be compatible. The Honeywell website reccomends these valves are used: https://theevohomeshop.co.uk/radiator-valves/51-honeywell-valencia-vhl120-15a-manual-radiator-valve-with-lockshield-set.html?search_query=Valve&results=49

Is there a cheaper equivalent that I can substitute or do I have to use their ones specifically?

The plumber is not familiar with the evo home system so he's just doing the rad valve changeover. He can provide an electrician to wire in the BDR91 part. Am I foolish to think it's all just plug & play thereafter? Are there any plumbing considerations I need to be concerned with? I feel I am managing the job myself but I'm not sure I'm doing it correctly.

Is it OK to put a trv on every rad or must one rad be left open on the system? Also, there's an additional Hot Water module that's available for the system. Does this need additional pipe work? Currently there's no summer valve on the tank so I'm not sure what control I can achieve with the hot water add-on?

Any advice welcome..

garo · 25-09-2020 10:35pm

How much are you paying for parts plus install? Have you looked at getting it done through Electric Ireland with the SEAI grant?

Note you will need to bind all the devices to the controller. If you are at all technologically minded this is not a difficult task. There are plenty of places you can find instructions.

Note that Honewell Evohome can only control 12 zones so either you will have to pair up your rads in the same zone - so two rads will be slaves to one or two other rads. Or you could leave the two rads open - but that is not recommended.

You do not need additional pipework (manifolds etc.) for the hot water control system but you will need a motorised valve installed to open/close boiler input to the HW. The TRVs control if boiler feeds the rads and the motorised valve controls if boiler feeds HW. Every element can be controlled individually.

deezell · 25-09-2020 10:43pm

The ones in the post previous will do perfectly, you'll just need one per rad, leave the other end on as the lockshield trim, £4.50 instead of £20 per rad.
You say theres no summer valve which implies a single zone, CH and HW combined. With a full TRV fit, you can effectively heat HW on its own by calling the boiler via a sepetate HW relay or module, the TRVs will all be closed. HW will always heat for any TRV call as its obviously open circuit, possibly gravity fed, but you need not worry about a bypass then when all TRVs are closed.
To have CH calls without HW, you will need a motorised valve installed on the HW circuit, with a small bypass on the boiler as now all circuits can be closed
Finally, we're all a bit foolish here, some have it really bad, so you'll fit right in. Evohome is the holy grail for some.

Grant Stevens · 25-09-2020 10:52pm

garo wrote: »

How much are you paying for parts plus install? Have you looked at getting it done through Electric Ireland with the SEAI grant?

Note you will need to bind all the devices to the controller. If you are at all technologically minded this is not a difficult task. There are plenty of places you can find instructions.

Note that Honewell Evohome can only control 12 zones so either you will have to pair up your rads in the same zone - so two rads will be slaves to one or two other rads. Or you could leave the two rads open - but that is not recommended.

You do not need additional pipework (manifolds etc.) for the hot water control system but you will need a motorised valve installed to open/close boiler input to the HW. The TRVs control if boiler feeds the rads and the motorised valve controls if boiler feeds HW. Every element can be controlled individually.

Thanks so much for the reply. I have sourced the kit online and it works out cheaper than going to Screw fix. The pairing/ binding part doesn't phase me at all. I'm handy with that stuff. What is important is that I determine what valves to put on the rads so that they will be compatible with the trv heads. Do I have to go with the Honeywell V120-15A valves or are there some generic valves out there that I can use. The plumber will not be providing a complete install, he's simply getting 14 radiators trv - ready by changing the current valves over to trv valves but now I'm worried he might install valves that may not suit my TRVs as he's not doing the full job for me, I'll be putting those on and doing the bind stuff, etc.

I am aware that there can only be 12 zones but I will combine some of the rads on the same zones eg the kitchen has 2 x radiators and the hall has 2.

There's a few issues I can't wrap my head around. Currently the heating system is on/off ie. no real control. This means any time we put our heating on, the water tank will heat up. With the new controller plus 14 TRVs in place, say I switch the boiler on but have all rads off, would this be another way to heat water only? Are there any dangers I need to be aware of with the new system?

The plumber was adament that zoning our house is a big job and didn't recommend it re: the usual 3 x zone system (downstairs/ upstairs/ water). He said there's too much work involved with ripping up floors etc. So this motorised valve you mentioned for the water, is that an easy thing for him or is there pipe work? With the motorised valve installed, what would I need to purchase to get this to 'speak' to the evo home control panel?

He came out to price the job today but hasn't given us the quote yet. He did mention that each radiator would be €30 for valve changeover. He said he has an electrician that can do the relay switch for us.

I asked him about the grant but he said this particular job wouldnt qualify as it doesn't satisfy all the prerequisites required.

lucast2007us · 25-09-2020 11:14pm

Grant Stevens wrote:

I asked him about the grant but he said this particular job wouldnt qualify as it doesn't satisfy all the prerequisites required.

I may be wrong, maybe Deezel or garo might confirm but
In order to receive the Grant the below works need to be carried out from my understanding:
Installation of a Seven Day Timer and Temperature Control to an Existing Boiler
Installation of Zonal Control over at least two zones in the home (heating and hot water)
Installation of Time and Temperature Control of electric immersion
Installation of a Boiler Interlock
The installation / modification to include an additional Heating Zone OR The installation of Thermostatic Radiator Valves on at least three radiators but no less than half of all radiators.

Grant Stevens · 26-09-2020 10:54am

I have gone to the electric Ireland Web portal to request a consult. I think this will be the better way to go. The plumber I've made contact with does not know the evo system and I feel we may miss some critical aspects of installation.

Hopefully EI will be able to assist. Thanks for the replies folks ðŸ‘

iba · 26-09-2020 11:40am

deezell wrote: »

Yes. Start with these. Then virtually any TRV you buy will fit without adaptors.

If you want to replace your rads with new one, you can put these at both ends, the second one acting as the manual valve as the little plastic cap in the picture rotates on the thread to push the pin closed if required to trim the radiator flow and balance the system response. You remove this cap to fit a TRV head. Depending on how old your radiators are, you may not be able to get exact panel size replacements, sizes have changed since the 80's-90's, so the newer sizes will be a bit longer or shorter, requiring extending or cranking of the riser pipes. Heres one on mine I had to do to fit a new twin panel rad replacing a late 80's original. Note the new TRV body from Stevensons.

Thanks deezel,

I've ordered six of those 30m Body Valves.

Can I ask, are you saying that not all the Tuya Thermostatic valves are the same? Only some fit on these body valves?

I tried google to see if it would answer the above question but it doesn't.

On Aliexpress, there are countless shops selling the Tuya valves but I can only find a couple of shops that mention Tuta valves and 30m x 1.5.

Oh and is Saswell (also shops on Aliexpress selling Saswell) and Tuya the same or is it that Saswell just use the Tuya app?

Thanks

garo · 26-09-2020 5:56pm

Grant Stevens wrote: »

I have gone to the electric Ireland Web portal to request a consult. I think this will be the better way to go. The plumber I've made contact with does not know the evo system and I feel we may miss some critical aspects of installation.

Hopefully EI will be able to assist. Thanks for the replies folks ðŸ‘

EI is really the only game in town when it comes to grant aided Evohome installation. The system is a bit complex but if you are willing to patient you can get it all done. I paid 1680 for a 12 rad install with everything included (BER, motorised valve, bonding for upgraded earthing).

You could get all the parts and do it yourself with help from an electrician and plumber for a little bit cheaper but not much. When I priced the parts they were coming to about 1100.

deezell · 26-09-2020 6:39pm

iba wrote: »

I've ordered six of those 30m Body Valves.

Can I ask, are you saying that not all the Tuya Thermostatic valves are the same? Only some fit on these body valves?

I tried google to see if it would answer the above question but it doesn't.

On Aliexpress, there are countless shops selling the Tuya valves but I can only find a couple of shops that mention Tuta valves and 30m x 1.5.

Oh and is Saswell (also shops on Aliexpress selling Saswell) and Tuya the same or is it that Saswell just use the Tuya app?

Thanks

It was yourself that said the TRVs your were looking it at only fitted RA, and derivatives. Any Tuya TRVs I've seen alk seem to have the common M30 1.5 screw thread connection. Just to avoid confusion, the Tuya TRVs are controllers, not valves. The valve is the chrome bit a controller attaches to. I added a link to Tuya M30 equipped valves. All these chinese devices can appear under different named.

Grant Stevens · 26-09-2020 8:03pm

garo wrote: »

EI is really the only game in town when it comes to grant aided Evohome installation. The system is a bit complex but if you are willing to patient you can get it all done. I paid 1680 for a 12 rad install with everything included (BER, motorised valve, bonding for upgraded earthing).

You could get all the parts and do it yourself with help from an electrician and plumber for a little bit cheaper but not much. When I priced the parts they were coming to about 1100.

I couldn't agree more. I would rather hand it over to someone knowledgeable than try the 'save a few quid route'. The plumber I had in is not familiar with the EVO home setup (that in itself should have raised alarm bells!).

Can I ask, how long did it take to get a response from Electric Ireland? I'm not in Dublin either so I wonder if that might add to the wait time?

iba · 26-09-2020 8:22pm

[/QUOTE][/QUOTE]

deezell wrote: »

It was yourself that said the TRVs your were looking it at only fitted RA, and derivatives. Any Tuya TRVs I've seen alk seem to have the common M30 1.5 screw thread connection. Just to avoid confusion, the Tuya TRVs are controllers, not valves. The valve is the chrome bit a controller attaches to. I added a link to Tuya M30 equipped valves. All these chinese devices can appear under different named.

Hi deezel and thanks

Yeah cause I looked at the fourth picture in this link:

https://www.aliexpress.com/item/4001245603510.html?spm=2114.12010615.8148356.2.639d2562VpRyQl

But in the specifications it does say M30 1.5

Sorry for my wrong wording regarding valve and controller; thanks for the correction, appreciated.

Regards

garo · 27-09-2020 12:54pm

Grant Stevens wrote: »

I couldn't agree more. I would rather hand it over to someone knowledgeable than try the 'save a few quid route'. The plumber I had in is not familiar with the EVO home setup (that in itself should have raised alarm bells!).

Can I ask, how long did it take to get a response from Electric Ireland? I'm not in Dublin either so I wonder if that might add to the wait time?

I contacted them late March. They did a house survey within s couple of weeks and system installed first week of May. So six week total turn around. I am in Dublin though.

Grant Stevens · 27-09-2020 3:52pm

garo wrote: »

I contacted them late March. They did a house survey within s couple of weeks and system installed first week of May. So six week total turn around. I am in Dublin though.

Thanks for the info. I have submitted my expression of interest via their Web portal so hopefully will hear back soon ðŸ‘

peposhi · 28-09-2020 11:22pm

deezell wrote: »

You already have the 3 zone climote controller from your previous install? you'll just need the extra wireless stat for CH zone 2. If the controller is wired in a new location which is suitable for measuring the temperature of zone 1 (say the hall or lounge), then the internal stat is fine for there, otherwise put it on a wireless stat also. If you're happy with that, go for it, wiring is a diy job, one sim sub is all you need. It's technically not a very well featured sysyem though, more like a 3 zone control timer with app access.

Thank you for getting back to me...
I’ve been away from boards for a little while.
Yesterday I bought a Climote (second hand) and will be hoping to get it installed....

I have an EPH R37-HW. I removed the panel and have the wires terminated as follows:
1-L
2-N
3-HW
5-Main house
7-Extension

I’ve got 2 wall thermostats wired in a box on the other side of the heating zone controller’s wall.

From what I understood - all zones are NO...

Looked at the the Climote...
Am I correct in saying that terminal 3/4 and 6 are the NO once where I have to connect the relevant wires?

deezell · 29-09-2020 10:53am

Correct, 4, 3 and 6 replace 3, 5 and 7 on the EPH. Tge commons on the Climote are not prewired, so link the live to 1, 2 and 5. Your image is too low res to see btw

Static M.e. · 30-09-2020 1:04pm

Hi all,

Big thread. I'm hoping someone can help. I would like a recommendation to upgrade my Immersion Switch, which has on\off and bath\sink, to a switch that I can use with an app or switch on with a timer for an hour.

Thank you.

emaherx · 30-09-2020 4:41pm

Static M.e. wrote: »

Hi all,

Big thread. I'm hoping someone can help. I would like a recommendation to upgrade my Immersion Switch, which has on\off and bath\sink, to a switch that I can use with an app or switch on with a timer for an hour.

Thank you.

Most of the ones I've seen, even ones claiming to be immersion switches are underated and potential fire hazards. But the best solution would be to install a suitable contactor and then you can safely control it with virtually any smart switch.

deezell · 01-10-2020 1:12am

emaherx wrote: »

Most of the ones I've seen, even ones claiming to be immersion switches are underated and potential fire hazards. But the best solution would be to install a suitable contactor and then you can safely control it with virtually any smart switch.

True, at 13a rating they're at the absolute limit for a 3kw immersion. This item is interesting, din rail mounted relay switch with 16, 32 and greater contacts which has Wi-Fi built in. Its not a current overload or s/c breaker, so would need to be wired from the existing immersion breaker to protect it. The 32a one will more than do for a single element immersion, or a bath/ sink twin one but with no remote control of the bath/sink element changeover. Cheap solution, wire it between the existing switch and its breaker. Put it in a mini din rail box, or If you're competent, you could pop it on the din rail of your main breaker box, or get a sparks to do it.
https://www.ebay.co.uk/itm/264771934737

xckjoo · 01-10-2020 9:38am

deezell wrote: »

True, at 13a rating they're at the absolute limit for a 3kw immersion. This item is interesting, din rail mounted relay switch with 16, 32 and greater contacts which has Wi-Fi built in. Its not a current overload or s/c breaker, so would need to be wired from the existing immersion breaker to protect it. The 32a one will more than do for a single element immersion, or a bath/ sink twin one but with no remote control of the bath/sink element changeover. Cheap solution, wire it between the existing switch and its breaker. Put it in a mini din rail box, or If you're competent, you could pop it on the din rail of your main breaker box, or get a sparks to do it.
https://www.ebay.co.uk/itm/264771934737

The Shelly 1PM is rated to 16A and I think it should be able to handle the bath/sink switching but I need to sit down and have a proper look at the circuit diagrams for it. It's been on the "To Do" list for a while

Edit: Better to hook one of these up to a contactor to handle the load and use the Shelly to turn on/off. See emaherx's post below

Brusna · 01-10-2020 10:08am

deezell wrote: »

True, at 13a rating they're at the absolute limit for a 3kw immersion. This item is interesting, din rail mounted relay switch with 16, 32 and greater contacts which has Wi-Fi built in. Its not a current overload or s/c breaker, so would need to be wired from the existing immersion breaker to protect it. The 32a one will more than do for a single element immersion, or a bath/ sink twin one but with no remote control of the bath/sink element changeover. Cheap solution, wire it between the existing switch and its breaker. Put it in a mini din rail box, or If you're competent, you could pop it on the din rail of your main breaker box, or get a sparks to do it.
https://www.ebay.co.uk/itm/264771934737

Very interesting indeed. I’m using a Sonoff TH10 on the hot water cylinder to switch a contactor in the consumer unit to control the immersion.

So the Sonoff detects the temperature in the cylinder and turns the immersion on and off between two set points.

I had a spare core on a cable between the hot press and the consumer unit so it was easy enough to setup.

With the unit you linked I think this could be done wirelessly by using scenes in the eWeLink app.

Could be a handy option for anyone who wants to control the immersion based on temperature instead of the usual time based control.

emaherx · 01-10-2020 10:15am

deezell wrote: »

True, at 13a rating they're at the absolute limit for a 3kw immersion. This item is interesting, din rail mounted relay switch with 16, 32 and greater contacts which has Wi-Fi built in. Its not a current overload or s/c breaker, so would need to be wired from the existing immersion breaker to protect it. The 32a one will more than do for a single element immersion, or a bath/ sink twin one but with no remote control of the bath/sink element changeover. Cheap solution, wire it between the existing switch and its breaker. Put it in a mini din rail box, or If you're competent, you could pop it on the din rail of your main breaker box, or get a sparks to do it.
https://www.ebay.co.uk/itm/264771934737

I'd be very reluctant to use these on an imerssion, the high curent switching of an immersion heater is very hard on relay contacts. Those devices are generally have poor quality relays which will burn out quite quickly even if they are reated at 32A

xckjoo wrote: »

The Shelly 1PM is rated to 16A and I think it should be able to handle the bath/sink switching but I need to sit down and have a proper look at the circuit diagrams for it. It's been on the "To Do" list for a while

As above, the shelly probably has a higher quality relay but it will realy be tested switching an imersion on and off. The extreamly small size of the shelly relay is enough to put me off. A good quality contactor is not going to add massive expense and can be controlled by the shelly but will greatly improve reliability and safety of operation. It will also lead to easier maintenance in the future as even if contactor fails its easy to replace and no need to reconfigure/pair new smart device.

Really lads I've seen enough standard manual switches fail due to arcing in their reletivly heavy duty contacts to know those tiny relay contacts will burn in a fairly short period of time.

Brusna · 01-10-2020 12:13pm

emaherx wrote: »

I'd be very reluctant to use these on an imerssion, the high curent switching of an immersion heater is very hard on relay contacts. Those devices are generally have poor quality relays which will burn out quite quickly even if they are reated at 32A

Just wondering why you are reluctant to use a similarly rated smart switch over a traditional contactor. I’d have thought a 32A smart switch has the same chance of failure as a 32A contactor.

deezell · 01-10-2020 12:37pm

Brusna wrote: »

Just wondering why you are reluctant to use a similarly rated smart switch over a traditional contactor. I’d have thought a 32A smart switch has the same chance of failure as a 32A contactor.

He's assuming the wifi controlled din rail contacor has rubbish contacts compared to a standard voltage controlled contacter. A few € extra buys the 50a version of this. Its purely a resistive load, so the arcing will be minimal. My only issue with din rail breakers and contactors in general is their cycle rating, are they made for multiple operations in a short time? I'd imagine 3 or 4 HW immersion calls during a day wouldn't tax it.

emaherx · 01-10-2020 1:00pm

The quality of these smart devices comming from China mostly, I'd also seriously question the claimed ratings on some of them.

And experience, I've seen what the inside of many Schneider Electric contactors looks like and having looked inside the smart switches I can't see how they'd claim to be the same ratings.

This is a fairly common story around the net.
https://support.itead.cc/support/discussions/topics/11000012976

just looking at the size of the relays inside the smart switch, you'd barely fit the concats from a decent Schneider Electric inside one of those let alone the coil.

Home heating automation

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