Boiler Noise

[andrewt]

Bit of a yarn this with a combination of things happening at the same time.

Had a new radiator fitted around a year ago and almost immediately after I found water intermittently flowwing out of the C/H header tank pipe.

Called a friend a friend of a friend who is a central heating engineer said it was 90% likely to be my boiler t/stat so he ordered one without doing a thorough investigation and came and changed it. The T/stat didn't fix the problem however I eventually traced the cause to my hot water cylinder . When I changed the cylinder I had to drain the whole system down.

Since the cylinder has been replaced I now have a lot of bolier noise. I did put a one shot treatment into the system but it doesn't seem to have worked. The t stat control needs to be right down (below 1) to get it to switch itself off . It is controling however I think it is getting very hot before it switches out. I have a suspicion that the t/stat is incorrect and that the old one was OK.

Are T/stats with different ratings available? i.e. could this be the problem? OR could it simply be the system needs flushing?

I kind of suspect it's the t/stat.

If anyone has any thoughts on this I would be grateful.

Thanks

 

[croydoncorgi]

Yes - there are lots of different types of boiler thermostats (and NTC sensors, and ....) and if you don't tell us what boiler you've got , how are we supposed to guess? Also, many boilers have TWO thermostats: one which regulates temperature and the other cuts out on overheating. I assume you're talking about the temperature control?

 

[andrewt]

Hi Croydon corgi,

Yes I am referring to the temp control t/stat. The boiler model I have is an Ideal Standard E Type series 2 conventional flue gas boiler. Model number CF.40/60. Quite a dinosaur i know

Not sure if this has a temp cutout t/stat or not.

Perhaps this info may help with the diagnosis

 

[croydoncorgi]

If water is 'flowing' out of the vent, it's probably being PUMPED out - as a result of a partial blockage somewhere in the system. In these cases, the path via the vent and F&E tank becomes the 'path of least resistance'. Such a blockage could also cause the boiler to overheat due to lack of circulation.

If it's just dripping out or coming out in 'spurts', you're probably correct - the boiler is overheating or even boiling.

If the boiler burner runs continuously unless the T/stat is 'below 1', then the boiler should be OFF until it's fixed! Quite likely its the wrong thermostat or faulty or (maybe) the sensor probe is not fully inserted into the pocket on the boiler heat exchanger. Follow the thin copper tube coming from the back of the stat and check. There should be heatsink compound on the probe to maximise heat conduction.

 

[andrewt]

Checked the temp t/stat today and it does work however there is lots of popping and banging going on before it gets any where near cutting in.

Everything seems to be working OK but for the noise.

What could it be?