Boiler gugrling noises and turning on unprompted overnight

[lukemartyn78]

Hi,

My Potterton boiler has started to made gurgling type noises when the central heating turns off in the evening - but it only seems to happen on random nights. The noises continue all night and even though the central heating and water timers have turned off for the night, the boiler randomly ignites and seems to be heating up only 2 radiators in the house (upstairs bedroom and bathroom).

As I said this has happened a few times now but on random nights. The only link I can think of is that it may happen on the same evening that a bath has used up all the hot water however I can't explain why this would effect the central heating??

Any help, thoughts or advice would be appreciated!

 

[D_Hailsham]

Which Potterton boiler?

 

[lukemartyn78]

Potterton Prima F - not sure of the age of it, only moved in a month ago!

 

[D_Hailsham]

Potterton Prima F - not sure of the age of it, only moved in a month ago!

Thanks.

Do you have one motorized valve (left pic); or two (right pic)?

View media item 5946 View media item 11762

 

[lukemartyn78]

there are 2 motorised valves on different pipes and it looks like the electric cable links the 2 together.

 

[Gasman28]

Is the boiler installed in a garage or loft?
Does it have a frost stat?

 

[lukemartyn78]

its in a kitchen cupboard. Not sure about the frost thing - afraid I'm not too savvy with these things!

Thanks

 

[D_Hailsham]

there are 2 motorised valves on different pipes and it looks like the electric cable links the 2 together.

Is one valve on a pipe to the hot water cylinder and the other on a pipe which disappears, possibly under the floor?

Is there a cable actually linking one valve to the other, or does the cable from each valve go into a large junction box?

If the boiler is in the kitchen, it's unlikely for you to have a frost stat.