mexico super 3 ideal boiler making banging noises

[ceg]

hi this is a 15? year old boiler and serviced about 4 months ago. been away for the week with it left on for an hour a day. got home and turned it on, cranked up the thermostat as was rather nippy in the house and its banging and humming and sounds like a bumble bee is stuck in the pipes!
bled the cirulating pumps and the rads doesnt seem to be any air stuck and the noise seems to be coming more from the back of the boiler.. is there any other diy stuff we can do before we call the plumber? thanks c x

 

[Hugh Jaleak]

Possibly a circulation issue. Have you checked there is water in the system? Small tank in loft, should be about a 1/3rd full. Did you get water out of the rads and pump when bleeding them?

 

[ceg]

hi rads are getting hot, plenty of hot water out of taps, water coming out when bleeding - didnt seem to be any air. although after bleeding did seem a bit better but perhaps wishful thinking.. does sound like its coming from inside the boiler although prob be deafened as had my head stuck in the boiler room bleeding the pumps! back of the boiler looks to have a couple of wter pipes into a big black box - so starting to think plumber is needed! once CH been on awhile does seem to get a lot better def worse when starting up and in that first hour, after that seems to be quieter and intermittant.. does this make sense?

 

[ceg]

well we've had a plumber around who first put in anti-scale stuff didnt seem to make any difference, then again a few weeks later and put in anti-sludge stuff which made a huge difference within space of a few hours.. he says hes got to come back and drain the system but have now noticed the banging is starting to come back! also been up in the loft today and noticed condensation forming in there and that the expansion tank seems to have almost a continual stream of water going into it which is hot and causing steam - is this normal? should there be a lid - ob not an airtight one! help! thanks c x

 

[Hugh Jaleak]

Ideally should be a decent lid on the F+E tank. The system shouldnt be 'pumping over' into the tank. Possible the system may just need a good clean out. Keep an eye on it, chemical clean may suffice, if not then a powerflush might be needed.

 

[ceg]

thanks - will fit a bit of wood over the top (similarily to the bit on the cold water tank!) when the plumber comes to drain the system down will have a chat..
its frustrating as we ripped almost everything out of this house and managed to fix/change/update it all ourselves bar the microbore pipe octupussy thing and the boiler, and now we're stumped!!
bit concerned about a powerflush and microbore pipe-should we be?

 

[Hugh Jaleak]

Get a plastic lid if you can, wood rots over time, seen plenty of disgusting wooden lids on tanks.....

Microbore due to its size can block with crud far more easily than 15mm pipe. Octopus you refer to is I think likely to be the manifold where the microbore branches off to the rads. You will need a heating engineer to do a powerflush, dont think it would be a problem, the work should be guaranteed anyway. Once its clean and working make sure its dosed correctly with inhibitor!

Check the flush stops the pumping over into the F+E tank, if this carries on then it needs looking at further.

 

[ceg]

hi thanks for the advice. just been up to the plumbing shop and they havent any in at the mo - nor none the right side so think its back to plastic and sheet of wood..

anyhow been fiddling with the pump speed (this was something else the plumber had changed but couldnt tell us why one pump was set to one and one was set to three.) anyway when we slowed th pump back down to one as we had orginally had the continuous trickle in the attic stopped. so hopefully it will sort out the condensation. assuming its too much pressure in system caused by too high a pump speed? is this correct, also why would having sludge/corrosion in pipes cause overflow?

c
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