Boiler coming on at night when not set to

[BetzPrim]

Hi there,

I've had the same set up for almost 7 years but recently have developed this problem. It started when I turned my heating on in Nov. I'm at my wit's end.

(In the summer I pressed and hold the frost button on my thermostat so it wouldn't heat up during the summer, as I always have done. In November, I turned the thermostat back on.)

My thermostat Salus RT501RF(TX) is set to come on at certain times of the day, which it does. Though it also flashes up at night, heating the entire house to sauna levels, despite it not being set to.

I have checked and rechecked the thermostat settings. It is absolutely not set to come on. It's set for 9pm and then 8am. Why is the heating coming on in the middle of the night. I don't know what time exactly it is coming on as I'm sleeping. It's 4am now and the heat has just woken me up as the house is a sauna. The heating is off but the thermostat reading is 21(!) and the radiators are cooling down. So it has been on but I'm not sure what time. So I don't know if the "flame" symbol would've been on the thermostat. Methinks I need to stay awake during the night!!

I've read manuals, blogs, websites again and again to find a solution and cannot find one.

I've literally never had this issue before. Boiler has recently been serviced, which I hoped would fix the problem. It didn't.

Boiler is an Eco Elite 25 Combi ErP

If anyone can help it would be great.

Thanks

 

[DP]

Do you have a frost stat installed?
if not, try disabling hot water pre heat

Possible the boiler not functioning correctly if second suggestion heating your rads

With everything cold on that boiler, grasp hold of the left hand pipe (22mm pipe), get someone to run the hot water tap.
If pipe starts heating up and gets quite hot, that is the cause.

 

[ianmcd]

Boiler has recently been serviced, which I hoped would fix the problem. It didn't.

Did you tell the person that serviced the boiler that you were having this problem ?

 

[shabbaranks]

Is the thermostat wired or wireless? We had exactly the same issue (different boiler) and it turned out to be the batteries in the thermostat. Although we didnt use cheap ones we needed to use very good ones which seemed to sort the problem (stopped turning itself on).

So sounds strange but worth a shot if wireless?

 

[Mottie]

Did you tell the person that serviced the boiler that you were having this problem ?

When I take a car in for service, I always ask if there are any other problems. Got caught too many times with people thinking that a service will put everything right!