Salus thermostat lost connection with receiver

28 Jan 2018
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United Kingdom
Hi there, I would really appreciate some help if possible. I have an Ideal Instinct boiler and a Salus RT510TX thermostat. Last night the Salus thermostat stopped connecting with the receiver- the red light on the receiver is flashing red, the heating no longer comes on and it doesn't respond to anything I do on the thermostat.

I tried re-pairing by pushing the Test/ Pairing button on the Salus, the screen says SYNC and counts down from 10 to 1 but nothing changes- the red light is still flashing and the thermostat isn't connecting with the receiver.

Is there something different I can try? Thank you so much in advance for your help
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Try removing a battery from the thermostat, then turn off the power to the receiver, wait a few mins and turn the power to the receiver back on, then replace the battery in the thermostat and push the test/pairing button that will be like a new installation and should work
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Thanks so much ianmcd, that worked and the thermostat re-paired. Very happy, you are a star!
I'm an ordinary householder with a Vaillant Ecotec boiler and Salus ST620VBC controller which I've had for 9 months. Yesterday and today I've got up to cold radiators though the heating should have been on for half an hour or more. The symptom is the red light flashing rapidly on the Salus back plate in the boiler. Each time (so far) I've switched the boiler off and on and that's cured it temporarily. After a few minutes the controller sends a signal to the boiler and it all fires up. I've now found Salus' explanation for this symptom on page 40 of their little manual (and PDF file online):-

When the ST620 is operating in AUTO mode, if the Boiler Control has not received a signal from the ST620 after 1 hour, the Boiler Control
will turn off the boiler, and the LED indicator will flash constantly (two times every second).
Once the Boiler Control receives a valid ON or OFF signal, the Boiler Control will control the heating system accordingly. that seems to say that the controller and backplate are not communicating. That's odd because the controller is in the same place that I've kept it for nine months, eight yards away from the boiler where the radio waves will either have to go through two domestic walls or bend slightly through two doorways. Salus says it'll communicate over 100 metres of clear air, or 30 metres normally so it should be OK. I'll try and sort it and keep you posted.
In short, the solution appears to be MOVE THE CONTROLLER NEARER THE BOILER and restart the boiler.
The background: I wrote above on 18.11.18 at 9.35am, above that the Salus controller had gone wrong twice in two days, in the morning.
The solution: It appears to be the controller not communicating with the backplate in the boiler for an hour, when the radiators switch off and the red light in the Salus backplate in the boiler flashes quickly. (The hot water still worked for us). Putting the controller nearer the boiler seems to make them communicate better.
The problems with this solution: This does not explain why the Salus controller worked for 9 months, then failed two mornings in a row. Maybe the battery is weakening. Maybe it's a bug or a hardware problem. Maybe another cause altogether.
Hope this helps!
Interference would be my guess! Have you had a new router, ring doorbell or any other such RF or WiFi devices installed recently? Or any of your neighbours for that matter?
Thanks very much dilalio, you may well be right, that the Salus controller could have failed to communicate with the backplate in the boiler because of some other broadcast in the house or by the neighbours. We haven't changed anything, the neighbours could have done. So, we're keeping the controller in the same room as the boiler so it's easier for them to communicate. Regards to all, best of luck and please post any solutions you find. Nigel
Only issue is that having to keep the controller in the same room as the boiler rather defeats the purpose of having a remote controller/thermostat!
If this IMGP7319_20_21_tonemapped.jpg is the thermostat, then is seems a common problem, I had it with mothers house is slowly reduced the range it would work away from base until in the end it was 2 foot away from base. Lucky is was a second thermostat and the other one continued to work.

We are told the thermostat should be in a room normally kept cool, so as summer comes it will turn off boiler earlier, on the lower floors as heat raises, in a room without outside doors, and with no alternative heating. I don't know your house, my where I have lived no such room, although last house was open plan so a single thermostat between the two rooms worked reasonably well.

However mother old house and this one, we have doors, OK old fashion idea, but many homes still have them, so we need multiple thermostats, what we normally use is TRV's (Thermostatic radiator valves) and in theroy no need for a wall thermostat, in practice however we like to adjust the home temperature through the day, having rooms cooler when we retire. And when the temperature is lowered without some central switch of some sort, the boiler would be cycling off/on/off all the time and wasting fuel.

So some wall thermostat is desirable to turn off boiler when temperature is reduced, but still allow it to fire up if the night is really cold.

Easy option is a thermostat linked to TRV heads, but a number of wall thermostats in key rooms all wired in parallel can do the same job.

We are told do not put a TRV on the radiator where the wall thermostat is, and if there is only one wall thermostat, and it is in a room as described earlier then yes, but most homes that room does not exist so we use the hall, which clearly has an outside door, so a TRV and wall thermostat is required, the TRV will open when the outside door is opened, then throttle back so other rooms have chance to also heat up before boiler turns off, which means the lock shield, TRV, and wall thermostat in the hall are crucial to be set correct if keeping rest of house warm.

However it is likely any other heated room could be used.

Faults in the settings can mean rooms not warm enough, I have this problem at the moment with my own home, and am experimenting with boiler output temperature, but rooms can't over heat, as the TRV's will limit the temperatures in each room as long as set correctly.

So you could put the wall thermostat next to base and have it run the boiler all the time, and no room will over heat, OK may use a little extra fuel, but it would work OK.

I will admit I do not set all my TRV's to turn down over night. These setting will not do much to reduce temperature over night,
however my programmable wall thermostat is still working, so at midnight the room will cool as main wall thermostat has turned down,
I have set it to 16 which is nearly the same as off, as unlikely to cool to 16 by 8 am. But I could set all the electronic TRV's to also cool down. I must admit the old types with *123456 are a bit hit and miss, as one has to guess what 20ºC is, normally between 2 and 3 so one wonders why they go to 6?

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