Potterton Suprima 40 Noise and Cutouts

[VS]

Hi - this is my first post on this forum so first up apologies if I leave anything out. I have done a lot of reading around on here already which has been enlightening and depressing in equal measures. I moved into my current (and first) home just over 2 months ago and inherited a 9 year old Potty Suprima 40 in working order. House and plumbing are also 9 years old. I have a few issues ...

1) "Normal" working conditions involve a fairly deep hum which can be heard from most rooms in the 3 bed house - is this normal?
2) Occasionally the "hum" volume escalates to something approaching NASA lift off level for a minute or so before returning to normal. Sticking my neck out here and guessing that this is not normal.
3) I have had to bleed quite a lot of air out of a bathroom radiator 3 times in the time I have been here already. All other rads are fine, all bleed clear water except for black stuff from lounge radiator.
4) The pump (situated upstairs by tank, boiler is downstairs in kitchen) always makes a "running water" sound, I have no experiences with pumps, are they usually audible? Tried bleeding, no air.
5) May be my imagination but seems to be taking longer to heat some of the further reaching rads downstairs - this may just be because its a bit colder out ... ?
6) During normal use boiler will shut off from time to time, green LED flashing, for a minute or so before firing up again. Is this normal?

Occasionally (once or twice per day) it fails to restart and locks out, requiring me to reset. PCB is 2nd of their board types, 5102160.

Previous owner had a British Gas homecare package and boiler was inspected in August 06 - am considering signing up with them and then giving them a call out in a month or so, what do you think my chances are?

Grateful for any suggestions and ideas!

 

[Agile]

You need to treat the sludge before signing up with BG.

The later PCBs are more expensive but are also probably a little more reliable too.

Statistically I doubt that the BG arrangement will be better value in the long run but should give you peace of mind perhaps.

I suggest that the PCBs should last at least three years on average.

Tony

 

[VS]

Thanks for the reply

You need to treat the sludge before signing up with BG.

Are you saying that the noise etc maybe down to sludge in the system? Was reading a post earlier about flushing the system and using FERNOX to treat, is this along the right lines?

How often should the system be flushed and cleaned? I live in a hard water area by the way.

I wondered about this but thought it was strange to only have 1 radiator kicking out black stuff.

I was under the impression that calling someone out to replace the PCB would be several hundred pounds by the time you factor in their parts markup and labour charge - I could replace it myself but wonder about any safety issues which that might cause, is it OK to simply slam a new board in and fire up again, or do checks need to be made?!

 

[nickso]

You need to treat the sludge before signing up with BG.

The later PCBs are more expensive but are also probably a little more reliable too.

Statistically I doubt that the BG arrangement will be better value in the long run but should give you peace of mind perhaps.

I suggest that the PCBs should last at least three years on average.

Tony

you do not need to treat the sludge before getting a BG contract....they will just refuse to undertake certain work caused by it. you will still get the benefit of certain parts of the contract and in certain circumstances if its been on contract very recently they wont even inspect it.

pcb's will last as long as they last...there is no set time for their demise

 

[VS]

OK - having sat and watched the damn thing for a while, I notice that while operating the boiler seems to go off every 10 minutes or so, the flashing light code showing "boiler temperature control satisfied". It usually then fires up again after a few minutes. I don't know what this means, is it normal?

I guess its not too much of a leap from there to the conclusion that occasionally it fails to restart resulting in lockout. So my real question is - what is causing the boiler to go off so regularly while running, any clues?