Home heating automation

Theres a wall thermostat and i can turn on heating automatically twice a day but thats it, seems to be a pretty old system.

Waiting on full breakdown of the quote but my understanding is that every radiator will get fitted with a TRV also, so more than just the black edition that you mentioned

Relieved to hear that, I was browsing a UK forum yesterday, and a poor sod wanted to know was £1500 a good price for replacing the attic plastic water tank, maybe £100 worth of new tank, drill it and reconnect cold out, ballcock, overflow, and home for tea by the afternoon. Fk me.

.

Quick question, for a house that was never properly zoned are the smart TRV's any use?

Thank you. The EPH seems to be a mains powered hot water stat, it's not long for this world

Since my original post I have had the my boiler replaced l, the plumber removed the zone value for the hot water (this was a solo run).

So now I am not sure if I still have a 3 zone system or is it technically a 2 zone now?

I know if I have both manual zones switched off and the timer clock kicks in it will heat the water only.

To those who are closing off their radiators (although the correct term is convectors), you might be inadvertently causing your boiler to be LESS efficient. There are a hell of a lot of variables and science that goes into heating your property and simply closing off your radiators and/or turning the thermostat target down by 1 degree is not likely to have a huge affect on your heating bill.

The first thing you need to determine is if your boiler is a condensing boiler. If it's not a condensing boiler then get one installed yesterday because no matter what you do, your heating system efficiency is going to be poor.

Assuming you do have a condensing boiler, you will want your boiler to go into condensing mode as much as possible and this only happens when the return temperature is under 55'c (the dew point). Now if you're going around closing off your radiator valves then it's possible that the hot water returning to boiler won't be under 55'c and the boiler wont enter into condensing mode, resulting in less efficiency.

Also keep in mind the second law of thermodynamics;

[QUOTE]The second law of thermodynamics is a physical law based on universal experience concerning heat and energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects (or "downhill"), unless energy is supplied to reverse the direction of heat flow.[/QUOTE]

If you're keeping rooms cold by closing the radiator valves, then any heat from outside those rooms will move towards those cold rooms which is not what you want.

One of the other things to consider when it comes to your boiler efficiency is the flow temperature. The flow temperature affects your overall energy consumption and therefore your ESB bill. You want to get your flow temperature as low as possible while still remaining comfortable. Flow temperature adjustments do become complicated if you have a hot water cylinder though.

On the topic of Smart Home Heating Systems, Tado is the only system to go for because they're compatible with the vast majority of boilers, allow set back temperatures, is weather compensation compatible, and can modulate the boiler if the boiler supports it. Modulating your boiler is great because it adds another level of efficiency to your heating system. It's likely that your current boiler is overrated for your property and it's burning at (for example) 24 kWh when all you need is 10 kWh.

Thanks deezell, much appreciated. I've had a look at the wiring of my current system and I've put together a simplified wiring schematic showing now and future state. Let me know if that's somewhat right. I should be able to give that to an electrician and just ask them to wire it up and test. To be fair, I'd almost be tempted to do it myself but the list of projects is already long...

Schematic current system

The grey boxes are either fused distribution boxes (see pics posted previously) or outlets. There is a wire from Home Zone controller to boiler. It's the same size as the wires from the HW stat. Is that 230V SL?. Not exactly sure what the item coloured in green is? Is that a pump?

Based on your previous posts I've put together this future state wiring schematic

I'm assuming the existing 230V powering the Home Zone could be reutilised as above? The earth leaving on the southside of the wiring centre is going to a physical earth point or would the earth from the mains be sufficient?

I assume N - N from 2- 3 and L - L from 4 - 5 are just short pieces of wire for bridging/connecting?

Cylinder stat wires 8 and 9 can be switched around right?

Can the current grey wire running from Home Zone to boiler be reutilised to go from 10 to boiler? Do I need a separate wire to go to the pump?

Let me know if you see any red flags.

Cheers

EDIT: Ghost comment.

Don, make sure you don't put a TRV too close to any stats.

1. Receiver for the hive is a simple wire in for the mechanical timer.

2. If its only used for CH, it can be set relatively low for maximum condenser efficiency, 55-60.

3. If it heats HW while CH is on then it will be simple enough to set up HW only by adding a diverter valve or zone valves. If it currently doesn't heat HW then it might need additional plumbing and pipework, maybe even a new cylinder if your current one is immersion only.

As it heats the HW when heating the CH, then 60 is probably as low as you should go.

Regarding point 3, the HW cylinder is connected to the boiler, and heats HW during a timed event, so it is just a case of using a zone valve to turn off the flow to the CH when a timed HW event occurs on the Hive. Just one motorised valve will allow you the heat HW only. A plumber will have to identify where the hot flow splits to HW and CH paths, and insert a motorised valve in the CH flow. This valve is operated by the Hive CH live, and this valve will have a relay which closes when CH in on. This relay will supply live to fire the boiler, combined with the HW live output from the hive receiver. Either of these lives will then fire the boiler to heat both HW and CH, or HW only.

A second valve can be fitted to give independent CH and HW. When you have the Hive installed and controlling CH, find a plumber who will install one or two motorised valves to enable HW only timing from the hive. You can also add a mechanical thermostat to the HW cylinder to stop a HW timing event when the HW reaches a set temperature on the stat. Note that the boiler flow temperature should be greater than the temperature set on the stat, to ensure heat transfer when the boiler is firing, and operation of the cylinder stat when its threshold is exceeded. Such settings tend to conflict with setting the boiler for a low flow temperature to optimise efficiency. This was discussed just a few posts previous.

If you don't already have mechanical TRVs on your rads, then get a plumber in to replace the valves with ordinary TRVs valves with M30 thread. Don't scare them off with talk of smart apps and stats. Once you have these valves on the rads you don't need a plumber to replace the mechanical TRV heads with smart ones, it's a DIY job, and configuration of the mounted smart TRV heads to the app is a techy thing, not a plumbing thing. Same goes for replacing whatever thermostat and/or timer or controller you currently have to operate your CH. It's mostly a small amount of wiring, and then some app configuration, again, mostly DIY, well up electricians and some plumbers could manage the swap, or someone familiar with light electrical wiring. Once you have the hardware wired in, the app stuff is DIY. If you get someone in to do everything, be prepared to pay big.

Did you have sperate HW before you got the Hub controller? Some old installtions had a wall stat and a mechanical timer, the timer would fire the boiler which would always heat the HW, either by gravity or pumped.The wall stat would either operate the circulation pump to the rads in a gravity HW system, or open a motorised valve to CH in a pumped system, so CH could be turned off allowing only HW heating. Many so called upgrades such as Hub CON troller, or free single zone stat offers from energy companies to switch supplier, were installed in place of both timer and wall stat, which prevented the system from heating HW only. No only that, but the energy companies registered your device as energy saving upgrade and automatically got a huge wedge of wonga in credits on your behalf. If you got your Hub C. in this way, you may already have exhausted your entitlement to a grant.

Is that €1500 an estimate for the prurchase of the hardware only, or the entire supply and fit? if its hardware only, get down to Screwfix and buy your own. Tado wireless starter kit in Black plus 12 Basic smart TRVs, (3 by 4 packs), €750. Similar price for Hive plus 12 TRV, or Drayton kit 2 and a dozen TRVs. You could have this up and running just by getting the receivers for any of these wired in place of the Hub Con, an hours work (though preferably next to the boiler where the HW relay of any these would be available for later upgrade to independent HW). Note that if you have 12 TRVs all turned off, you merely have to fire the boiler with the receiver HW relay for hot flow to supply the HW cylinder only, as all CH paths are closed. This is simply a matter of combining HW and CH receiver outputs to the boiler. A call for HW only will not open any TRVs

I doubt you'll get anyone to supply that much kit and fit and configure it for €1500, especially if they're on the approved grant list of installers. I've no faith in grant aided upgrades, they're automatically double or treble what would be reasonable, and the grant is swallowed by the huge margins.

Mine working at the moment, v7.5.0

Ditto, surprised it didn't auto-update. Dark mode looks cool, but you've to turn dark mode on for your whole phone to enable it.

I read a piece maybe two years ago that development on Evohome is halted, it basically is what it is, until it isn't someday. I can't remember exactly where, but it was more than just speculation.