Valves and pump keeps breaking - flushing or inhibitor?

[Davidben83]

Hi,

I would really appreciate advice because I am getting a lot of mixed messages from plumber and internet.

I moved into my three bed semi a year ago. There is a tank in the loft and a hot water cylinder in an airing cupboard. The boiler is about 15 years old and inhibitor was added about five years ago. Unfortunately, however, we have had constant problems:

- hot water stopped working, heating working. Plumber changed valve and seemingly fixed it
- heating working erratically and then very rarely but hot water fine throughout the house. Plumber changed hot water pump;
- A month later (now), the heating has started working erratically again. It appears that the hot water in the system does not get past the relevant valve very often. That valve was replaced in 2012.

When the heating works, the rads are fine.

I am not sure what to do. Could it be sludge build up? If so, should I:

- Add powerful inhibitor (and could this break the system if sludge is preventing leaks)
- power flush (and ditto about breaking system)
- replace system
- look for a non-sludge related cause.

I am a bit lost because replacing valves at £200 a time is not pleasant and I am not sure what the underlying problem is. Sludge seems to obvious answer but other than valves/pump breaking, there aren't the other symptoms (e.g. boiler noisy, rads not heating).

I would really appreciate advice.

 

[Plumber90]

I very much doubt it is due to sludge. Does the boiler always fire up fine when you turn the heating or hot water on, or does it fail to turn on.

 

[triplexxx]

It might be programmer, you need to be able to test with multimeter to prove.

 

[Davidben83]

Hi, thank you Plumber90 and triplexxx for responding, I really do appreciate it.

To take your questions in turn:

Plumber90 - it is interesting that you do not think it is sludge. I have checked whether the boiler has turned on three times and each time it has and the heating system has worked. I will keep trying tomorrow to see whether the boiler turns on when it doesn't work and report back. What are your suspicions? Thank you.

triplexxx - I think that the plumber tested the current of the programmer before changing the hot water pump. He said it was OK. Is that you have in mind?

 

[jeff the gasman]

There are some really rubbish valves in the merchants that only last for a couple of years. Make sure you are getting quality kit fitted.
Jeff