Help connecting wireless thermostat to boiler

Why?

You need the thermostat to make where you occupy most most comfortable. Personally I have my thermostat in the room used every evening for watching TV etc.

Also I think in today's world you need to make sure both devices can use the

I’d recommend the Hive system. It isn’t the cheapest but it is established, the user interface is very good. I find the remote access excellent.

If your existing controller uses an MK14 back plate ( the plate the controller clips to), installation is very easy - you may not need any wiring changes.

We already had normal TRVs so I didn’t change to hive ones - especially as we don’t use some rooms and just set them low.

I used the data from the Hive app to adjust the on/off times for the heating. I was surprised how early in the evening I could set the heating to turn of yet maintain the room temp, although the house is well insulated.

The manual for the device I'd linked to (ref

"The thermostat should not be installed in the same room as a radiator that’s controlled by a thermostatic radiator valve (TRV). Installing the two in the same room may result in the central heating being permanently on."

The bathroom is the only such space.

Is that guidance wrong?

On a new system you would select the optimum place for the thermostat (possibly you main living room) and not fit a TVR in that room. The bathroom may not have had a TVR as a safety mechanism - somewhere for the pump to push the water when all the TVRs in the system shut off.

Just because your bathroom is currently the only room without a TVR it doesn't mean that it is the best place for the room thermostat. I doubt if anyone reading this has the room thermostat in their bathroom - for good reason.

The advice is correct in that the room heat should not be controlled by both the room thermostat and a TVR BUT you are possibly drawing the wrong conclusion about locating the room thermostat. Fit the thermostat, say, in your main living room and replace the the TRV with a normal lockshield valve. Rather than removing the TVR you could just unscrew the TVR head which leaves the valve fully open (just make sure that the valve controlling pin that you can see when the head is removed is free to move and not stuck - it will be stiff so just lay the flat of a spanner or body of a pair of pliers on the pin and press down fairly hard and release. The pin should remain in the fully up position)).

See

The main living room, which is a large "L" shaped lounge + dining, has

But are you in effect saying that the thermostat is acting as the TRV, ie effectively replacing it? That makes sense I guess.

No, its rules for fools, and guidance for wise men.

The point is not to have to call for heat in a room in which someone has shut the radiator off.

Just consider what will happen in a room with a radiator thermostat set for 15°C and the radio stat is set to 19°C.

Ah - the lounge is the room that will always have rad stats on max :)

That will work.

Might not:-;

I once attended a call out where the customer placed the wireless stat on the radiator......

But yes it should work. If the TRVs are fully open then the stat should do it's job.

Sounds right to me.

We have the thermostat in the hall, the rads there don’t have TRVs.

Originally, the thermostat was in the sitting room and we didn’t have TRVs or Hive.

Having a thermostat in a hall is quite common.

I'm a bit new to all this new fangled stuff but ....

I think I'm get it.

That would have been the natural choice for me except I've now decided that heating the hall, which is a full room size, is an extravagance with costs going up the way they are. This whole exercise started (see other thread) with my conclusion that the hall radiator, which has no valves, needs to be switched off.

The main downside is the change in temperature traversing from front of house (living quarters) to back of house (sleeping quarters and study).

Just need to be disciplined in keeping doors shut.

I suspect that, with, Smart TRVs, you could ( for example) avoid heating the bedrooms during the day (assuming they are unused), give them a burst in the evening and morning ( if that is what you like), and apply a similar approach in other rooms where the use is predictable. The problem is where to put the thermostat - it shouldn’t be in a room with TRVs ideally. I don’t think it is a hard and fast rule - you may be able to make it work by ‘clever’ programming of the TRVs.

The advantage of having a wireless thermostat is that you can move the transmitter around and you can experiment with it in the hall or in your living room.

Where people place the thermostat may depend on how many people in the house and how many rooms being used a lot of time for living. If there are only one or two of you and normally spend most of your leisure time in one room then that is possibly the ideal location. In my house one room is heated to an elevated temperature (20 to 22C) and the rest of the house controlled by TVRs and kept to maybe 16 to 18C (bedrooms a bit cooler)

This whole exercise started

Pedant mode: it will have two values but probably require a spanner to close them one of them to the off position.

Yes, this is probably the way to cut costs. Definitely close doors to rooms that you don't use much. Close the door in the room where you need keep in most heat.

I'd not put the thermostat in the living room - normally it'd go in the hall, so that it can control the temperature without interference, say from people turning a fire on.

In my own house, I have a thermostat and a motorised valve for each room, so it doesn't matter if someone puts a fire on; the sun happens to be shining on that side of the house; we're cooking, etc. Each room will get up to the temperature set for that room, at that time of day, and then shut off, unless it cools again. None of the other rooms are affected.

So in that case you would set all three TRVs to max temp, or remove their heads.

It replaces it, in the sense that when the room reaches your preferred temp it will turn off the heat. The difference is that it will do it for all of the heating, and not just that room.

Yup if you have a room that is not used, turn down its TRV and shut the door on it. It will stay cooler / cold compared to the rest of the house.

I have the Hive system and have the Hive thermostats on all radiators except the bathroom which is the official bypass for the CH system. Despite the advice not to install the thermostat in a room with a TRV the thermostat is in the lounge which has a single TRV controlled radiator, I have found no issues with the setup. The smart TRVs are not like normal TRVs in that they can operate heat on demand. So if the lounge TRV demands heat it overrides any setting on the main thermostat, likewise if the TRV senses the temperature is adequate it will shut off the radiator immaterial of the main thermostat settings. The beauty of the smart TRVs is you can literally heat as many rooms as required or simply one room.

There are other smart systems that do a similar thing, I am quite pleased with the Hive system.

Richard

Most stats will be programmable some some extent - allowing different at least the choice of a normal and a "set back" temperature to be invoked for different time slots. Some may allow different temps for each time slot.

TRVs can do some of what zoning achieves, but they can't usually select different heating times for different zones.

(for example I have an upstairs zone and a downstairs one (bedrooms and living space if you prefer). In the morning the bedrooms get heated before the downstairs, but the downstairs, will carry on being heated after the bedrooms are no longer heated).

If you are using the hive hub (that is the bit that makes the stat "internet connected" - and enables the "smart" facilities, then that is usually hard wired to the router. However it can be right next to it. It is not wired to anything else, and uses zigbee wireless protocols to talk to the hive stat (and the stat uses the same to talk to the receiver).

Note you don't need the hub at all if you don't want the smart capabilities (like being able to control the heating from your phone, or integrate with voice assistants to tell them to turn the heating up or down vocally. Without the hub it will just behave as a bog standard wireless stat.

Almost certainly not the best place for it. (Unless you spend all your time in there!)

(discussed elsewhere in this thread)

That looks like the version without the hub. So no smart integration, but also no internet connection required.

It can go anywhere you like - it does not need to be on show. It will have a mains connection, and a wire to the call for heat input on the boiler.

Yup it will let you set the times and room temps. Note that it will not control the boiler flow temp - this would still be manual. To control boiler flow temps automatically you need weather compensation.

For most users, setting a flow temp to "low ish" (where low ish will depend on the size of the rads, the level of insulation etc) will be adequate for most of the year. You may want to tweak it up a bit during very cold spells if you find the heating can't get the house up to temperature, or if it takes too long.

Sounds like you are on the right track.

Looking at page 31 in the boiler manual:

and page 10, "single channel wiring" in the receiver manual :

Remove the link wire between pins 1 and 2 on the boiler. Wire the Neutral pin on the boiler to the N pin on the stat. Wire pin 1 on the boiler to pin L on the stat Wire pin 2 on the boiler to pin 3 on the stat

The boiler is then supplying a live and neutral connection to the stat, and the stat is feeding back a switched live connection to the boilers call for heat.

If using conventional 3 core flex with the normal Brown, Blue, and Earth wiring colours, you can use the earth core for the switched live from the stat (pin 3, on the stat, pin 2 on the boiler), but you should over mark it with brown insulating tape at both ends to indicate it is repurposed as a (switched) live and is not an earth connection.