Faulty SRV?

cuke2u

I have two wireless smart thermostats and four Tado SRV's in our property and they've all worked just fine from the start, aside for a teething issues with the receiver, five of the smart thermostats operate as they should and turn the heating on and off, either manually or to a schedule.

Yet one will only turn on the heating but refuses to turn it off again. I can hear the SRV's valve motor moving ok when I turn it on and when I turn it off again, the CH light goes off on the receiver but the boiler continues to heat, with the CH pump still powered up. Now normally I'd say this must be a stuck CH zone valve, we have a S plan, but it operates perfectly OK with all the other smart thermostats, they all turn on the heating and off again as they should and the faulty one has been fine up until the weekend.

I've checked within the app and they've all paired and have good battery life so it does not make any sense to me at all so anyone with any idea's?

wateroakley

@cuke2u Sorry to hear one of the SRVs is playing up. With 24 SRVs and two receivers in two family homes, I've not come across that type of fault? It sounds odd that the receiver light goes out but the boiler continues for just one SRV?

1. Configuration questions … Are all the Rooms set to a 'zone controller'? Or 'Independent' ? Are the Rooms configured with a Room Sensor as the temperature measuring device?
2. The TRV can be reset by removing the batteries, leave out for a minute or so, re-insert and refit. That will reset and recalibrate the TRV. While you're doing that, check that the pin on the physical TRV is not stuck.
3. The only physical thing I can think of is a sticky micro-relay in the receiver? But that doesn't make sense as a behaviour for only one of the four SRVs? When this happens, can you check if there is still power on the NO connection that would keep zone valve open?
4. If this doen't point to anything, I'd suggest you reach out to Tado support from the chat function on their main website pages.
5. FYI, the big onlne store 'A….' has the Tado kit reduced in their sale today, £39.99 for a SRV. Swapping with a replacement SRV or sensor would probably be the quickest way to establish whether you have a faulty device or something else.

HTH.

cuke2u

Hi @wateroakley and thanks for your response, my answers:

1. Zone controller and yes.
2. Tried that.
3. I don't know about that, can individual sensors keep the NO powered up and not just the receiver control this? As every other device is fine. Certainly the boiler, the pump and the zone valve are still getting power.
4. Done this and awaiting a reply, not holding my breath.
5. Good call, ordered another that I can use elsewhere. Although it's only been a year of Tado ownership.

Do these sensors have a reset at all so I can start from scratch or is it just delete the sensor and room to do this?

wateroakley

Hello @cuke2u 3. One device in an individual room will call for heat ON or OFF from the 'zone controller' (the wireless receiver). If you have a TRV and wireless sensor in the same room (or multiple TRVs), they work in tandem. The 'measuring device' should default to the wireless sensor and that is the master device that calls the receiver for heat ON or OFF. The TRV then acts as a slave.

4. Patience is a virtue. Especially when the heating doesn't work.

5. I've just ordered some add-ons too.

6. The devices should reset when you remove the batteries and leave them for a minute or two before refitting the batteries.

7. From the settings, you should be able to add the new TRV to the room and delete the old device. Alternatively, create a new room and devices and delete the old room.

HTH.

cuke2u

Thanks @wateroakley Yeah I know deep breaths, long history with the heating system in this house. We moved in a year ago and found that one radiator didn't heat up at all and three others barely got warm. Had a heating engineer come in to service the boiler recently and he diagnosed the pump and fitted a new one with the result being that we now had three stone cold radiators. I put some cleaner in the system, left it for two weeks then last week I was taking those radiators off walls to flush them out, then back flushed the pipes and fitted new valves to two of the radiators that were playing up.

The result was two radiators getting nice and toasty so I thought I was winning but this new issue emerged with that one radiator SRV.

Anyway, I've now tried one of the working SRV's in that room, after deleting the one that was in there, and it still wouldn't turn off the heating, then with the one that wasn't turning off the heating fitted to another room's radiator the SRV was working fine. So I think we can eliminate it being a SRV and put it down to ghost in the system.

Tomorrow I'm draining down the system again so as to complete the fitment of valves to two other radiators, as I ran out of time last week, so anything could happen. 😁 At nearly 70 I'm getting a tad old for this malarky.

wateroakley

@cuke2u Glad to hear the rads have warmed up. I'd be tempted to refit a manual TRV until you figure out what is happening with the SRV.

cuke2u

@wateroakley that's exactly what I've done for now. Just cannot fathom out why only that room when all the others work perfectly.