Help with correct thermostat purchase

[CMAC86]

Hey guys I'm back again, I want to replace the thermostat/receiver (if this is what they are named) that was installed with my boiler a few months ago with a WiFi enabled (Google & Alexa) one. Needs to control heating and hot water. I see two which are different (3A & 16A). Which would be the correct one I should buy for UK? My boiler is a Vaillant if that helps. Relatively new.

Below are pics of the installation as it stands. A wireless controller (not WiFi enabled) that control's the heating to (small receiver installed below boiler).


Controller

Receiver

Here is the image of the one I want to replace it with




Is this possible? Also can one run both those receivers off the same wiring so I can still keep the original controller and receiver? Or is this a daft question?.

If not I don't mind if I can install the new one and use the phone app to control everything (my family keep messing with the controller because they don't know how to use it!)

Would appreciate some input guys. Thanks alot,

 

[stem]

Your existing set up comprises of two parts:

1) A wired receiver that communicates with....

2) A wireless battery operated programmable thermostat. (You have labelled it a controller)

The thermostat you want to replace them with is a mains operated wired thermostat. It requires 230V to power it and will not work with a receiver. That means that the old receiver would be removed and the wires from it would need to be extended out to the position where the thermostat was located.

For a gas fired central heating system a device rated at 3A would be sufficient. Larger current ratings are usually for electric heating.

 

[CMAC86]

Your existing set up comprises of two parts:

1) A wired receiver that communicates with....

2) A wireless battery operated programmable thermostat. (You have labelled it a controller)

The thermostat you want to replace them with is a mains operated wired thermostat. It requires 230V to power it and will not work with a receiver. That means that the old receiver would be removed and the wires from it would need to be extended out to the position where the thermostat was located.

For a gas fired central heating system a device rated at 3A would be sufficient. Larger current ratings are usually for electric heating.

Thanks for your reply mate. So if I wanted to remove my existing setup I cannot replace with the one I planned on buying? Or can I?

 

[ericmark]

Many Vaillant boilers are OpenTherm enabled, so if going to completely replace maybe opentherm is better than on/off type.

 

[stem]

So if I wanted to remove my existing setup I cannot replace with the one I planned on buying? Or can I?

Yes you can, but you would have to remove both the existing receiver and thermostat, then the wires that now go to the receiver would be extended out to the new thermostat.

 

[CMAC86]

Yes you can, but you would have to remove both the existing receiver and thermostat, then the wires that now go to the receiver would be extended out to the new thermostat.

View attachment 212801

Ah yes mate I get it now, that's more work than I wanted to do, meaning I'd have to open up the boiler cover and wire in the new wired thermostat to the receiver inside. Not that I assumed it was a simple switch of wires but I thought I could achieve it.
___________________________
Actually scratch what I sad above. I think it is achievable, going by your diagram I just route all wires into the new thermostat?

Here is a pic of the back of the receiver unit

One cable going up into the boiler (assume connected to receiver inside) one going down and routed into the back of a 3Amp plug for power. I assumed I could remove the receiver there and rewire the new one in.


I may get in contact with the boiler installed and ask about options. Great appreciate your reply. Thanks alot mate

 

[CMAC86]

Many Vaillant boilers are OpenTherm enabled, so if going to completely replace maybe opentherm is better than on/off type.

I'll look into this thanks

 

[stem]

meaning I'd have to open up the boiler cover and wire in the new wired thermostat to the receiver inside.

Eh?? according to your photo the receiver is not inside the boiler...

With some combi boilers (but not all) to access the wiring terminals it is necessary to open up a sealed part of the boiler that could allow fumes to escape if not properly refitted. That is not a DIY job and should be done by an RGI (Gas safe) engineer who can then make sure it is properly sealed up again.

Therefore, I suggested that the receiver in your photo above would be removed, replaced with a junction box and then a new cable run out to the new thermostat.

If you want to keep the status quo, Nest or Hive offer the same set up as you have now; a remote thermostat and a receiver that would replace the two Plumb Centre items that you have now. From a wiring point of view, all that would be needed is to swap the receiver over.

 

[CMAC86]

Eh?? according to your photo the receiver is not inside the boiler...

View attachment 212812

With some combi boilers (but not all) to access the wiring terminals it is necessary to open up a sealed part of the boiler that could allow fumes to escape if not properly refitted. That is not a DIY job and should be done by an RGI (Gas safe) engineer who can then make sure it is properly sealed up again.

Therefore, I suggested that the receiver in your photo above would be removed, replaced with a junction box and then a new cable run out to the new thermostat.

View attachment 212813

If you want to keep the status quo, Nest or Hive offer the same set up as you have now; a remote thermostat and a receiver that would replace the two Plumb Centre items that you have now. From a wiring point of view, all that would be needed is to swap the receiver over.

Again thanks for your replies mate. What you suggested is what I wanted to do, the new thermostat would replace the receiver (I don't mind not having original controller as Ive named it) as I can control via my phone over WiFi. So I should buy a little junction box wire all the wires through that and a new wire going into the new thermostat screwed in place were the old receiver sits, That's what I wanted to do.

Thanks again

 

[EFLImpudence]

As Stem has said, there are other things (Hive, Nest etc.) made for your situation negating the need to run a cable to the thermostat position.


Still, it makes a change from people buying unnecessary wireless equipment when they already have the cable in place.

 

[CMAC86]

As Stem has said, there are other things (Hive, Nest etc.) made for your situation negating the need to run a cable to the thermostat position.


Still, it makes a change from people buying unnecessary wireless equipment when they already have the cable in place.

Thanks for your input mate. Appreciate it. I'm gonna contact the gas installer to see what he says. Thanks,

 

[ericmark]

With some combi boilers (but not all) to access the wiring terminals it is necessary to open up a sealed part of the boiler that could allow fumes to escape if not properly refitted. That is not a DIY job and should be done by an RGI (Gas safe) engineer who can then make sure it is properly sealed up again.

I have seen this said many times, however since when doing an EICR an inspector would need to check cable clamps and like are in place, that would mean only a duel trades person could do an EICR or he would need to give it a code FI which for rented property is a fail, so would be rather short sighted of any manufacturer to put the electrical connections where an electrical inspector could not inspect them.

I was told by a gas safe guy I should not have removed the cover on my mothers Bosch boiler, even though it was quite clear there was an open void under the boilers cover so clearly not sealed. So I would not remove a cover which clearly states gas sealed cover, but not seen one so marked as yet.

 

[EFLImpudence]

Surely that would be part of the gas inspection and not an EICR.

It is not part of an EICR to dismantle appliances.

 

[ericmark]

It is not part of IET installation inspecting and testing, it would be part of the inspection and testing of in-service electrical appliances, however it would be part of the government definition of installation, which includes anything fixed or intended to be fixed.

Of course down to the inspector, however if going to remove a socket to check for earth sleeve and grommets, then clearly also would check boiler specially if faults found on other parts of the central heating system.

Finding a tank thermostat with the only earth wire used as line, clearly all other central heating items would also need inspecting. I would say for non DIY work most of poor installation work is either kitchen fitters or heating engineers. The number of times I have found no earth taken to a heating related appliance I have lost count of.

 

[denso13]

however it would be part of the government definition of installation, which includes anything fixed or intended to be fixed

Where there is a fire and back boiler in a typical chimney would you remove the gas fire to check the back boiler wiring?