Boiler stops trying to fire in the evening?!?

[RGP]

Hi,

I hope someone can shed some light on a strange problem I'm having with my boiler.

We have a wireless thermostat to control when the heating should come on. In the morning the boiler fires up and everything works as it should most of the day. However, at some point in the evening even though the boiler control is still set to ‘on’ and the thermostat is telling the boiler to fire (and the control unit is receiving this signal and looks to be passing it on), absolutely nothing is happening. The boiler doesn’t try to fire, and it isn’t showing any faults – it’s as if it isn’t being asked to fire. If I turn the hot water to ‘on’ it fires up correctly.

The next day the boiler will start up again in the morning and the cycle repeats itself each day.

When we have been away for the weekend I have changed the thermostat so that the heating only comes on for a few hours in the evening to warm the house up before we get back. This seems to work OK. I can therefore only assume that during the course of the day some effect is building up until eventually the problem manifests itself, and then overnight the effect wears off.

We have just had the boiler serviced and they found no problems with it. Given that it fires if I turn the hot water on I can only assume that there is a problem with the control box which takes the signals from the thermostat and the boiler control unit. However, I don’t know what on earth it could be.

Any help or suggestions would be gratefully received. If specific details are needed please let me know.

Thanks in advance

Richard

 

[oldplumber]

turn off your wireless broadband in the evening, does that help?

 

[RGP]

Thanks for the suggestion. We only turn on our router when needed. I'm afraid that the boiler had already stopped working tonight before we turned it on. The thermostat does seem to be communicating correctly with the control unit - the receive light flashes and the light is on to indicate that it should be telling the boiler to fire.

 

[oldplumber]

replace batteries and go thro set up proces again, could be another rf stat is interfering with yours, so change the dip switch settings on yours if need be

 

[gasmarc]

i wonder if the neighbours rf could affect it , i wasnt aware you can change the frequency

 

[RGP]

Thanks for your comments and suggestions. I have attached a picture of the boiler setup which may help.

1. Shows the thermostat indicating that the boiler should be coming on
2. Shows the receiver is getting that signal and should be passing that on
3. Shows the boiler control set to On
4. Shows the boiler doing nothing

My understanding is that between them 2 and 3 should be enough to make the boiler fire.

Does 2 not prove that there is no problem with the communication between the thermostat and the control unit? I would be more than happy to be told I am wrong on this.

I hugely appreciate all your help on this.

Thanks again

Richard

 

[ecowarm]

I know nothing of keston boilers but does it have an anti cycling function .... delaying the firing to save energy?

 

[Kathy C]

I've got this problem as well - did you ever get it sorted - I have got EON coming to see my boiler/thermostat tomorrow but would be nice to know if you found out what the issue was, thanks

 

[RoryD]

set up receiver:
1. power mains off, slide both sets of battery drawers until display goes blank
2.power on
3.On receiver press the overide button once - green light on
4.press the lower button, immediately followed by upper button (both at same time), red light blinks several times and goes out - let go of all buttons
5. Stand at LEAST 1 metre from receiver with room stat and close the RIGHT hand drawer folled by the LEFT hand drawer
you now have to reset the temperatures on the programmer

This is on all the time, if the temperature set for a particular time is lower than this setting (and it will be for the summer) then it won't come on.
I bet by switching to manual and increasing the temperature (press +) it'll come on

 

[Kathy C]

Thanks, reset the receiver and also increased the CH temp and that seems to have done it, thanks a lot.

 

[RGP]

Thanks to everyone for their help and suggestions. It turns out to have been a fault with the thermostat somewhere.

Once things stopped working in the evening I would go through the commissioning process with the wireless thermostat, sometimes a few times, and eventually it would start working again. The next day it would pack up again though.

I decided that it probably wasn't the boiler, and just took a punt on replacing the thermostat units. Everything is now working perfectly.