Evohome boiler relay keeps turning off

[Brian E]

In my system I have the Evohome Controller, a boiler relay in direct line-of-sight about 4 metres away and 9 HR92 radiator valves.

The issue I am seeing is that quite often, but not always, the boiler relay will either not come on when there is heating demand from one or more radiator valves or it will come on for a minute or two and then go off again. When the green light does come on, I hear the relay operate, after which my Bosch Greenstar CDi Compact boiler fires up, so the relay is doing its job when it is activated.

As an example, I noticed that the temperature in my lounge and dining room had dropped to 1.5 degrees below the set temperature this evening. So I manually increased the HR92 controlling the towel rail in the kitchen by several degrees to increase heat demand, but it was several minutes before the relay turned on and then it only stayed on for a couple of minutes. So, I manually switched on the relay with the button on the relay box and now it has stayed on.

Can anyone tell me what might be happening here?

[Richard]

Are the air temps remaining stable?

evohome has to input energy into the system to maintain stable air temps. During some demand periods, there is a very small heating demand to 'top up' the rooms to the set temp and the system uses TPI to do this.