Please help with Alpha C23 Boiler!

[Nicola83]

Hi

I'm really hoping someone here can help. I've had Scottish Gas out numerous times regarding strange behaviour with my boiler but they can never get it to recreate the fault when they're out.

Basically the boiler will switch the heating on by itself irrespective of the temperature set on the thermostat. When it does randomly switch on if I put the temp up on the thermostat then put it down again the boiler goes off as normal. The boiler has been serviced and checked etc and appears to be running ok. The thermostat was changed yesterday and has made no difference.

Another thing I've noticed is that while it does this it doesn't seem to go fully off and the light that normally flashes when it's on 'standby' if you like or that's solid while working goes off completely and the boiler is still making a faint noise as if on but not completely.

Its to been doing this since about October time ao therefore I don't think its because the water temp inside is too cold (as per the manual) and is driving me crazy. I hope this makes sense to someone here and you can help me because I'm just desperate to get this resolved.

 

[Dotty]

Hi Nicola

When you say stat are you talking boiler stat or wall stat?

 

[IDCHAPPY]

Alphas are sh... not great boilers.
That's a strange one though, something must be asking the boiler to run though.

 

[kay-jay]

Have scottish gas linked out any external controls.
I would be disconnecting the roomstat and programmer one at a time if you have them.

 

[Anton]

Alpha C23 has built in frost protection. If the water temperature drops below 8 deg C it will override the external controls and bring the heating on. Sounds like the temperature sensor is out of range and needs replacing.

 

[Nicola83]

Hi

Thanks everyone for replying.

Croppie It was the room stat that was replaced the other day. It seems to be working as when you put it on the boiler comes on and when you put it off the boiler goes off... So that's something I supppse!

Kay jay I'm unsure if they have to be honest... Maybe mostly because I'm unsure what you mean. Apologies but I'm totally ignorant with this stuff

Anton I saw that in the manual and had wondered if that perhaps was the problem. The cupboard the boiler is in has a window and gets very cold. I put a thermometer in there last night and it hit 15*C. It wouldn't have been that cold when it first started doing it back in October though.

Also so in my efforts to help SG find out the issue I've let it run when it starts this behaviour this morning for about half an hour and it only heard the radiators very very slightly.

Hope this helps one of you so my mystery can be solved!!

Thanks again folks... Any and all help is appreciated.

 

[Anton]

You're not following what I was saying.
The room temperature can be 90 deg C, if the sensor is faulty it won't matter what the temperature of the water/room is, it will still try and fire the boiler up.

 

[Nicola83]

You're not following what I was saying.
The room temperature can be 90 deg C, if the sensor is faulty it won't matter what the temperature of the water/room is, it will still try and fire the boiler up.

Hi Anton

i understood what you meant. All I was saying was that I had put the thermometer in there last night. Just a bit of extra info

 

[IDCHAPPY]

He means it's possibly the frost stat in the boiler itself that could be faulty.
You need to get them or another engineer out to inspect it.

 

[Alpha man]

Primary sensor!, which is also the frost stat.

 

[jam1979]

The faint noise is probably your pump overrun