Home heating automation

The room thermostat can only control the zone valve. It is unable to control individual radiators.

The Drayton TRV's are able to open the zone valve even if the the Room thermostat is not calling for heat. Each TRV can open the zone valve when they require heat while any other radiator fitted with the smart TRV's will stay closed.

It's very clever in how it operates and the amount of control it gives. The heat from the sun has a huge effect on one side of my house. With the smart TRV's the heat shuts off on the warm sunny side while allowing the rooms on the shady side to continue heating. When i was using the room thermostats on their own this wasn't possible.

I haven't been using it long enough to be able to calculate whether it saves energy usage but it's more important to me to have the house heated so we're comfortable and warm rather than saving money.

The only real function i can see with my downstairs room thermostat now is to give a visual of the room temp without having to go into the app

loyatemu

even with just the room thermostats I figure the system is saving money (not entirely sure how) - usage in the last year was 2000 units (or ~ 7%) down on the previous year despite us being at home a lot more for obvious reasons.

I'd like to add the TRVs but unfortunately I don't have TRVs on the existing rads so it's a drain-down job requiring a plumber which means €€€

Paulzx wrote: »

It's very clever in how it operates and the amount of control it gives. The heat from the sun has a huge effect on one side of my house. With the smart TRV's the heat shuts off on the warm sunny side while allowing the rooms on the shady side to continue heating. When i was using the room thermostats on their own this wasn't possible.

dumb TRVs would probably achieve the same result though.

JimmyVik

I did something for someone with wifi plugs with energy monitors (€6 each) in them onto 2.5kwh panel heaters in each room in a D rated 3 bed bungalow.
Then we put wifi thermostats (€13 each) into each room. In the app we set up rules for time of day and temperature.
So now each room stays at the desired temperature at the desired time without fail.
And with the energy monitors in the app you can see exactly how much you heating is costing you.
Its been like that now since last year in one house. Ive others partly set up for other people.
In this one its keeping the bedrooms at 18c from 6pm until 9am (9hrs of that on night rate) and the living room and kitchen at 21C (was 23 but thats too warm, so trying 21 for the last while and its still warm) from 7am until 11pm is costing an average (bedrooms use less than living and kitchen rooms) of about €10-15 per room per month on a cold month. I can even see the cost each day for each room if i want to go into that level of detail. On a mildly cold week, like last week, it averaged €1 per room per day.
Still have to rig up the immersion and two bathrooms to have similar control.
But its very handy now with the app.
Can change to different scenes etc.
Spending far less on electricity than on oil.
I have a plan to rig it up to gps or something to trigger it when someone is on the way home from work. But that will be a while yet because everyone is at home all the time.
But im definitely a fan of controlling each rooms temperature independently.

I had dumb TRV's on beforehand and they don't give anywhere near the same control as the smart ones. I don't know whether the cost of the smart ones are recoverable over time

My upstairs zone still has all dumb TRV's controlled by the Drayton room thermostat and it works perfectly for that zone. I don't plan on putting smart trv's there unless i get them very cheaply

loyatemu wrote: »

can you link the external thermostat to one of the TRV, so you're measuring the temp from somewhere else in the room (I only have the basic kit, no TRVs)

what happens when all the TRVs in a zone are at the set temperature, does the zone shot off at the main valve?

If there are no open radiators on the Room thermostat zone, it could call the zone valve and thus the boiler while no rad is open to receive the flow, and thus the boiler will cycle. In the Tado config you can have the stat with no function other then as a relay for the TRVs to open the valve, it's relay calling the boiler. It can also be activated as the temperature measuring device for TRV(s) in it's physical location.
With Drayton the latter is not available afaik, and with a full TRV complement in the zone, the Room stat is redundant, and can probably be turned down to prevent unnecessary boiler calls. Indeed, the zone valve is redundant in such a scenario, it could be left locked open, it's actuator just working as a relay to fire the boiler, or removed altogether, with the zone HubR wired directly to fire the boiler.

deezell wrote: »

With Drayton the latter is not available afaik, and with a full TRV complement in the zone, the Room stat is redundant, and can probably be turned down to prevent unnecessary boiler calls.

Hadn't thought of it calling the boiler unnecessarily but that makes sense

DrPhilG

deezell wrote: »

With Drayton the latter is not available afaik, and with a full TRV complement in the zone, the Room stat is redundant

I thought that with a room stat and TRVs in the same room, the room stat acted as the master and the TRVs would respond based on whatever the room stat is reading?

That's my plan for the living room. Once the hallway has TRVs (next week) I was going to relocate the hallway room stat to the living room to give a better read on the temps as the TRVs tend to be a bit out of whack from the room temperature.

Not my experience. Each TRV is capable of operating independantly and can call heat to itself irrespective of the Room Thermostat settings.

I've also compared the TRV temp readings to the room thermostat readin by moving it around each room and they're pretty much the same

Step one of getting ready done. Plumber round today and redid the piping in the hot press and added the hot water zone valve.

The way our system was piped initially meant that the hot water from the back boiler always heated downstairs even when the downstairs valve was closed. He moved the valve so now we can heat upstairs only, if required. Will see how it works out this evening. Nice and neat job.

Next step is to decide on Drayton vs Tado. Tough enough decisions as there are pros and cons to both. Isn't one system that seems to have all the features I'd want....

chris_ie wrote: »

Next step is to decide on Drayton vs Tado. Tough enough decisions as there are pros and cons to both. Isn't one system that seems to have all the features I'd want....

The more features you have is directly proportional to the amount of time you spend walking around the house playing with valves, measuring temps and generally being obsessed with getting everything perfect:D

You'll turn into a heating nerd overnight. You should be sitting down relaxing enjoying the heat and comfort of you're home but you'll be up and down like a jack in the box measuring stuff.

My missus is ready to just turn the heat off altogether and sit in the cold instead of watching me going around playing with rads and analysing the app:eek:

Might be one for Deezel,

Currently i have the new Tado extension kit wired in gravity mode, so cable to circ pump and cable to boiler.

I’m getting a new boiler next week and plumber said there is connections for the pump on the boiler. I assume i can forget about these connections and just keep my existing wiring the same so that one relay controls pump and other controls boiler?

I should have said, at the moment the boiler is under the stairs and therefore providing gravity hot water, I’m moving it outside now so I’m thinking the gravity HW might be a problem?? Might have to go to fully pumped?

Wiring diagram for new boiler attached

Paulzx wrote: »

The more features you have is directly proportional to the amount of time you spend walking around the house playing with valves, measuring temps and generally being obsessed with getting everything perfect:D

You'll turn into a heating nerd overnight. You should be sitting down relaxing enjoying the heat and comfort of you're home but you'll be up and down like a jack in the box measuring stuff.

My missus is ready to just turn the heat off altogether and sit in the cold instead of watching me going around playing with rads and analysing the app:eek:

�� Yeah it’d be the same here. I’m walking around the house this evening messing with radiators!

No idea what’s going on with my system now. As mentioned before our the downstairs always heated when stove was lit even with valve closed. Plumber moved valve today so it would only heat when valve was open. Also added a valve to what I thought was the feed from the oil boiler.

Forward to now, I have stove lit and downstairs valve closed with upstairs open. Radiators in room with stove (3 of them) are still hot. Guessing flows there first before going back? Upstairs is luke warm at best.

Also the pipe which I thought was the oil feed into cylinder is getting hot and the oil hasn’t been on for a few hours.

I.e we have one coil fed by back boiler and another I thought was oil but it’s getting hot.

This make sense to anyone? Rather confused now and not working the way I thought it would at all!

Image attached, the pipes on the right are for back boiler and it’s own coil in the cylinder I imagine. The one on the left is the one I thought was from the oil and to which the new valve was added but it’s getting hot without oil evening being on.

maxamillius wrote: »

Might be one for Deezel,

Currently i have the new Tado extension kit wired in gravity mode, so cable to circ pump and cable to boiler.

I’m getting a new boiler next week and plumber said there is connections for the pump on the boiler. I assume i can forget about these connections and just keep my existing wiring the same so that one relay controls pump and other controls boiler?

I should have said, at the moment the boiler is under the stairs and therefore providing gravity hot water, I’m moving it outside now so I’m thinking the gravity HW might be a problem?? Might have to go to fully pumped?

Wiring diagram for new boiler attached

For gravity heating of the cylinder, there must be a level or rising path from the boiler hot flow to the cylinder flow in. The cold return must be below the hot flow to create a convection loop. If the flow and return are routed from outside by dropping under the floor and back up to the cylinder, gravity or convection will not occur, and the system must now be pumped to both cylinder and rads, with valves to isolate flow from the two zones, or at least one to close CH, with HW heating for any timed CH or HW event. With a single CH valve, the ext kit can remain in gravity mode, but with the HW terminal firing boiler AND pump, and CH terminal opening the valve. Alternatively, the ext kit can be reconfigured to fully pumped, HW terminal to the boiler/pump, and CH terminal to the CH valve, with the valve relay going to the boiler/pump switched live in conjunction with the HW terminal from the ext kit. If you have to fit a CH valve, fit a HW one as well, ect kit now opens each zone for independent heating, with the zone valve relays combining to operate the boiler/pumo for either.
Tado support can quickly revert your ext kit to fully pumped mode, with rac terminal going live for it's timed event.

chris_ie wrote: »

�� Yeah it’d be the same here.....
.....Image attached, the pipes on the right are for back boiler and it’s own coil in the cylinder I imagine. The one on the left is the one I thought was from the oil and to which the new valve was added but it’s getting hot without oil evening being on.

Heat from the cylinder will convect back into the pipes from the boiler, at least bacj to floor level if the valve is not a full seal. There may be some circulation pressure on this valve via the radiator circuit when fed by the stove pump.

deezell wrote: »

Heat from the cylinder will convect back into the pipes from the boiler, at least bacj to floor level if the valve is not a full seal. There may be some circulation pressure on this valve via the radiator circuit when fed by the stove pump.

Felt quite hot. Nearly as hot as the boiler one. Radiators are bit warmer up there. Not that much. I’ve closed ones in kitchen.

deezell wrote: »

For gravity heating of the cylinder, there must be a level or rising path from the boiler hot flow to the cylinder flow in. The cold return must be below the hot flow to create a convection loop. If the flow and return are routed from outside by dropping under the floor and back up to the cylinder, gravity or convection will not occur, and the system must now be pumped to both cylinder and rads, with valves to isolate flow from the two zones, or at least one to close CH, with HW heating for any timed CH or HW event. With a single CH valve, the ext kit can remain in gravity mode, but with the HW terminal firing boiler AND pump, and CH terminal opening the valve. Alternatively, the ext kit can be reconfigured to fully pumped, HW terminal to the boiler/pump, and CH terminal to the CH valve, with the valve relay going to the boiler/pump switched live in conjunction with the HW terminal from the ext kit. If you have to fit a CH valve, fit a HW one as well, ect kit now opens each zone for independent heating, with the zone valve relays combining to operate the boiler/pumo for either.
Tado support can quickly revert your ext kit to fully pumped mode, with rac terminal going live for it's timed event.

Crude drawing but you will see where the boiler will be placed and how the pipework will run, do you think gravity would still work in this case?

maxamillius wrote: »

Crude drawing but you will see where the boiler will be placed and how the pipework will run, do you think gravity would still work in this case?

If the boiler is going away from the house wall and pipes have to go underground, then no gravity is possible. If the boiler was placed against the house wall, with the hot flow going out on the level through the wall and rising to the cylinder, gravity works in this case.

deezell wrote: »

If the boiler is going away from the house wall and pipes have to go underground, then no gravity is possible. If the boiler was placed against the house wall, with the hot flow going out on the level through the wall and rising to the cylinder, gravity works in this case.

Yep got it now, looks like I missed that, will need to get zone valves installed now and change up the wiring.

Makes sense to get:
CH Valve
HW Valve
Cylinder stat

Or is it an option to go fully pumped but put TRVs on all the rads? So call for heat from any of the rads fires pump and boiler. Hot water timed event fires pump and boiler but all TRVs closed? Not sure that’s a done thing though is it?!

maxamillius wrote: »

Yep got it now, looks like I missed that, will need to get zone valves installed now and change up the wiring.

Makes sense to get:
CH Valve
HW Valve
Cylinder stat

Or is it an option to go fully pumped but put TRVs on all the rads? So call for heat from any of the rads fires pump and boiler. Hot water timed event fires pump and boiler but all TRVs closed? Not sure that’s a done thing though is it?!

That would work, its the same as my single CH zone valve configuration, with HW always heating for any event. With full TRVs, you could have a zone valve on the HW to control it independently, though you would need maybe one open rad or towel rail, or a small bore bypass between the flow and return at the boiler to allow circulation if all TRVs and the HW valve was closed.

deezell wrote: »

That would work, its the same as my single CH zone valve configuration, with HW always heating for any event. With full TRVs, you could have a zone valve on the HW to control it independently, though you would need maybe one open rad or towel rail, or a small bore bypass between the flow and return at the boiler to allow circulation if all TRVs and the HW valve was closed.

Presume I could wire a HW valve through a cylinder stat then aswell?

Will have a chat to the plumber, either way the scope has changed will need either a zone valve or full TRV setup. To be honest I wanted TRVs anyway so it’s not a big deal.

maxamillius wrote: »

Presume I could wire a HW valve through a cylinder stat then aswell?

Will have a chat to the plumber, either way the scope has changed will need either a zone valve or full TRV setup. To be honest I wanted TRVs anyway so it’s not a big deal.

You presume correctly.

It's worth mentioning that there has been some discussion of the need for a zone valve when a zone is fully equipped wirh smart TRVs. There may over time be less than perfect closure of these valve due to age, calibration, battery life etc, and its possible that you might have heat seepage when heating HW only during the summer. If you retain the zone valve then this is not an issue. Mechanical trvs would not be likely to fully seal either unless set to low thresholds, so the zone valve ensures no heat losses when in HW mode only, and prevents smart TRV anxiety for those who wander the corridors at night touching rads and checking apps.

Think I’ll go with two zone valves for now. I’ll have a job getting cables to them!! I need to change out the hot water cylinder also but leaving that until summer so will do the TRVs and cylinder stat then!!

Appreciate your input as always Deezel thanks!

Vikings

deezell wrote: »

You'll need what is known as the wireless starter kit, this incudes the ext kit, and if you don't already have a wired wall stat, you can connect the Tado stat wirelessly back to the ext kit. TRVs the next bit. If you want CH without HW, you'll need to add zone valves, but its not a biggie, HW is unlikely to overheat when the boiler is delivering heated water to the rads for CH, especially with the Tado, as it modulates the boiler burn for a cooler flow once the CH is near it's scheduled temperature.

Back again! So I ordered the wrong kit which was delivered today.

It's the wired version with no extension kit. My bad not working through the order properly (first time ordering from .de) but before I go sending it back .... If I swap the wired tado for my wired wall stat without changing my programmer or anything else will I gain some of the smart functionality? (And then order and fit the ext kit when it arrives for water)

Vikings wrote: »

Back again! So I ordered the wrong kit which was delivered today.

It's the wired version with no extension kit. My bad not working through the order properly (first time ordering from .de) but before I go sending it back .... If I swap the wired tado for my wired wall stat without changing my programmer or anything else will I gain some of the smart functionality? (And then order and fit the ext kit when it arrives for water)

Yes you will. You'll get full smart stat function. The ext kit is just for wireless stat connection and HW timer relay.

@deezell you mentioned the Tado has an off grid type feature where you can set the temperature but have it not call for heat. What’s that setting called? Was having a look through the manual to see what options are available and couldn’t see it.

Strange that it can’t be done on Drayton. I mean if you have schedules, surely you set temperatures for those schedules. If you don’t have a schedule what happens the TRVs? Are they fully open/closed? Or do you need to have a schedule all the time.

I contacted Drayton and they said the TRVs will always call for heat.

sebdavis

chris_ie wrote: »

@deezell you mentioned the Tado has an off grid type feature where you can set the temperature but have it not call for heat. What’s that setting called? Was having a look through the manual to see what options are available and couldn’t see it.

Strange that it can’t be done on Drayton. I mean if you have schedules, surely you set temperatures for those schedules. If you don’t have a schedule what happens the TRVs? Are they fully open/closed? Or do you need to have a schedule all the time.

I contacted Drayton and they said the TRVs will always call for heat.

Not 100% sure what you are referring to but on Drayton you can turn off each TRV for different period etc and have them come on later in day.

I don't use it but I did try and I could set the temp to off if I wanted.