Boiler Relay Wireless Range

[George Costacovich]

Hi all, we have a Victorian house with solid stone walls with a combi boiler serving it from a block built outbuilding next door.

Currently there's a Siemens RDJ10 thermostat in the hall which is not much good as the temperature is very different in the open plan kitchen diner.
I was thinking of getting a Honeywell T4R as a I previously had a CM927 which worked very well, but if I'm wondering if the wireless from the boiler relay in the outbuilding to the thermostat in the house is going to be reliable enough through all that stone and blockwork. Is it possible to wire the relay or can it be put where the existing thermostat is in the hall?

many thanks

 

[oldbuffer]

A trick I've found successful in the past is to put a flat coil of insulated wire behind the receiver, and run the other end of the wire to a convenient place near the transmitter. There is no electrical connection (hence insulated wire) but it acts as a sort of aerial to improve the signal. Bell wire is perfectly adequate.

 

[George Costacovich]

That's a good tip! But I was hoping to have the thermostat wireless so it can be moved around.

 

[BlueLoo]

You have to wire the relay/receiver anyway. Just make the wire longer....

 

[George Costacovich]

Indeed! But can the existing wiring that currently goes from the boiler in the outhouse to the existing thermostat in the hall be used?

 

[BlueLoo]

Indeed! But can the existing wiring that currently goes from the boiler in the outhouse to the existing thermostat in the hall be used?

Absolutely.

You can put the reciever where the old stat is, or, chase the line back to a more suitable position if needed.

 

[oldbuffer]

1. My suggestion does not involve any permanent electrical connection between receiver and transmitter. And the controller MUST be wireless
2. You could run the transmitter end of the wire to anywhere in the house. Then, provided there are no significant obstacles between transmitter and that end of the wire, you could move the transmitter anywhere.

 

[Harry Bloomfield]

I was thinking of getting a Honeywell T4R as a I previously had a CM927 which worked very well, but if I'm wondering if the wireless from the boiler relay in the outbuilding to the thermostat in the house is going to be reliable enough through all that stone and blockwork. Is it possible to wire the relay or can it be put where the existing thermostat is in the hall?

Nothing to stop you moving the receiver unit, to a more central location.

 

[stem]

Siting a thermostat correctly is crucial for the correct operation of the heating, I've lost count of the number of times I've been asked to look at a "faulty thermostat" because the house is too hot / too cold. when in reality the design of the heating system is poor, unbalanced, or the thermostat is in the wrong location. There are very few locations in a home that are actually suitable for a room thermostat to work properly.

Tips for Room Thermostat Location:
The room thermostat should be in a room that is not effected by other sources of heat such as an open fire, cooking equipment, or direct sunlight etc. It should not be somewhere drafty or too close to a window, especially if it's one that is opened in the winter.

Secondly it should be in a cool room, ideally the last room in the house to warm up. That way, the other rooms will be warm enough, (but not overheated because of their TRV’s) before the room thermostat switches the entire heating system off. To achieve this, it may involve downsizing the radiator in the actual room where the thermostat is located.

The radiator in the room with the thermostat installed should not have a TRV fitted. Otherwise the TRV can interfere with the correct operation of the room thermostat.

The thermostat should be mounted about 1.5 metres from the floor, and not close to, or above a radiator.

Preferably it should not be on an outside wall, (although if you have well insulated walls, this is not quite so crucial.)

It should be in an area where air can circulate easily, not in a corner, or hidden behind curtains, or furniture.

 

[George Costacovich]

The plan is that the new thermostat will live in the coolest room which is a big kitchen / diner / living area with bifolds at one end. However there are multiple rads in that room all with TRVs. But I'm hoping that as the T4R has a stand we can find the best spot for it. At the moment that room is so cool the TRVs end up being on full anyway.

 

[Harry Bloomfield]

At the moment that room is so cool the TRVs end up being on full anyway.

Turning TRV's up, will not necessarily make the room warmer. TRV's should be set to limit the maximum temperature you want in the room, usually around mid-way.

As suggested above, any room where you place the stat, should have a radiator without a TRV - though you can simply set the TRV(s) to max in that room, or remove the head(s).

 

[stem]

Sounds like a poor installation that has not been sized properly. To resolve it properly, sounds like you need more or bigger radiators in the kitchen / diner / living area so that it heats up more quickly than the hall does, then allowing the TRV's in there to control it and keep it comfortable. Putting a room thermostat in a room containing a kitchen that will no doubt get warm at times when you are cooking [unless you live on salad / sandwiches ] means that the heating in the rest of the house will go off when cooking is in progress. And when there's no cooking happening, imagine how hot it will be in the hall by the time the kitchen / diner / living area gets warm. Which of course assumes there isn't presently a TRV on the hall radiator where the room thermostat is located.

 

[ericmark]

The radiator in the room with the thermostat installed should not have a TRV fitted. Otherwise the TRV can interfere with the correct operation of the room thermostat.

I don't agree with that due to bitter experience trying to get mother's central heating working. The idea places for the thermostat is in a room kept cool, with no alternative heating, on the lower floors, and no outside doors, in real terms such a room rarely exists.

So setting the TRV to approx same temperature as the wall thermostat when for example the room is the hall, will allow fast recovery when outside door has been opened but before it reaches the wall thermostat temperature it has closed so in winter the boiler never turns off, OK assuming gas, not quite the same with oil.

I used Nest Gen 3 as I only had two wires and wanted to control both DHW and CH plus charge the unit although in hind sight not the best option.

My major error was I thought the hall would cool down rapid, and it does not, heating time can be varied with the lock shield valve, it is cooling time which is important. At first glance it seems my thermostat is in the idea place, centre of ground floor, between doors for shower room, living room, kitchen, and dinning room, but being centre of house it cools down too slow, and no amount of adjusting on lock shield or TRV can correct that, so I get a hysteresis in living room as waiting for hall to cool.

Oil does have a combi version, but really a cheat, it is a storage tank built into the boiler, the boiler can't modulate it can only turn on/off. With modern gas however the boiler modulates (turns down output) so it should never turn off in the winter, unless there is a change in the temperature called for.

This is where the TRV and wall thermostat in same room gets complex, if the wall thermostat turns down at a set time, then once the room has cooled it will keep switching on/off unless a modulating thermostat is used or the TRV is also programmable.

My hall radiator is opposite end of hall to thermostat. So looking at my TRV now it shows target 17°C current 19°C, the Nest Gen 3 shows 19.5°C and set to 19°C it should change at 1:15 am in another ¼ hour. The TRV changed temperature at 10 pm, so nearly 3 hours and hall has not cooled.

Living room has two radiators one shows 19°C the other 20°C so near enough to what is wanted. The other programmable TRV heads only show target. It is so much easier with gas, the TRV controls the boiler output, the wall thermostat is only there to stop it cycling in the summer.

Hind sight, would have been better with a wall thermostat that linked to the TRV heads, well I thought it would, when I got Energenie mihome TRV heads it said they worked with Nest, but it seems when Google bought out Nest they also removed support for Energenie.

It seems at the moment Drayton Wiser is the market leader, but uses wireless, main reason for Nest Gen 3 is it can use a pair of cables between the heat link and thermostat, and heat link is in flat below the main house so I was worried if the wifi would work through the floor.

There are others like EvoHome and Tado, all do a OpenTherm version if your boiler can take it.

 

[BlueLoo]

TRVs are old tech.

 

[bernardgreen]

TRVs are old tech.

The wheel is old tech compared to hover craft and maglev.