Screeching from somewhere in plumbing- Megaflo?

[The OP]

Hi All,


This is my first post on the forum, and I'd be very grateful for your thoughts on a problem we have had for a month, and which we have spent several £100s on, with no success.


Despite visits from 3 plumbers/engineers, we cannot get rid of a loud screeching/groaning noise occuring in our plumbing, which seems to emanate from, or near, or Megaflo unvented indirect cylinder. We have almost run out of ideas!


When the noise is loud, the pressure gauge wobbles slightly. But it never exceeds 1.4 bar, even when noise is at loudest.


The pressure relief and pressure reducing valves have been changed, and a shock arrester installed. All to no success. A heatrae sadia engineer said it wasn't the tank (though it really sounds like the noise comes from the megaflo, especially when you put your ear to it). He suggested we have the two zone valves looked at.


Before I spend yet more money- has anyone any ideas?


Many many thanks.

 

[The OP]

sorry, its in your cupboard , blue with BG multihead sign on. It shouldnt be hot when nothing is on anyway so if its spinning something is probably not switching off as it should. But, try pump first, just doesnt make sense why this happening only during night. Do you have heating/hw set off during night?

I really appreciate your help, but I am fairly certain I don't have a pump like that. There isn't one in the cupboard with the tank or with the boiler. Is that possible?

It doesn't just go at night, but that it is when it is most likely to happen. Neither the heating or hot water is on at night. Sometimes it happens several hours after heating/HW were last on.

 

[The OP]

sorry, its in your cupboard , blue with BG multihead sign on. It shouldnt be hot when nothing is on anyway so if its spinning something is probably not switching off as it should. But, try pump first, just doesnt make sense why this happening only during night. Do you have heating/hw set off during night?

Sorry! Don't know how I managed but that is the wrong YouTube link! That person def has a pump, but I don't think I do. This is my video-[video]http://m.youtube.com/watch?v=YEAJaz8o1dg&feature=youtu.be&desktop_uri=% 2Fwatch%3Fv%3DYEAJaz8o1dg%26feature%3Dyoutu.be[/video]

 

[SafeGasInstall]

1st this is really SPOOOOKY sound .....................

what are you switching on and of on your video ?

 

[galaxy_plumbing]

that sounds like a vibration on pipe caused by a faulty valve, probably stuck washer, at least i had something very similar once. Maybe its worth try to shut all valves and see if anything changes.

 

[Jonwells]

The chattering noise sounds like either over pressure or over temperature problems, is there any water coming into the tundish when the noise is happening.
Plus when the noise is happening, what is actually ON on the system, is boiler burner on.

 

[The OP]

The chattering noise sounds like either over pressure or over temperature problems, is there any water coming into the tundish when the noise is happening.
Plus when the noise is happening, what is actually ON on the system, is boiler burner on.

Thanks -
I'm not sure about the tundish- do you mean the gap in the pipe connected to the TPR valve? If so, then no- no water in the tundish.

When I recorded the video, nothing was on on the system- the heating and hot water had been off for several hours, and no water was being drawn anywhere in the house (intentionally, at any rate).

 

[The OP]

that sounds like a vibration on pipe caused by a faulty valve, probably stuck washer, at least i had something very similar once. Maybe its worth try to shut all valves and see if anything changes.

I know the noise stops instantly if I turn off the blue tap on the cold water inlet for the megaflo, just before the cold water combi valve. Does that tell you anything? I should add that that valve was changed a couple of weeks ago in an attempt to fix the problem, along with the 8 bar valve next to it.

What other valves should I check, do you think, and how would I do that?

 

[Rickster123]

Have you checked that you neighbour isn't having any issues??

 

[Dotty]

I know the noise stops instantly if I turn off the blue tap on the cold water inlet for the megaflo, just before the cold water combi valve. Does that tell you anything? I should add that that valve was changed a couple of weeks ago in an attempt to fix the problem, along with the 8 bar valve next to it.

What other valves should I check, do you think, and how would I do that?

In all honesty you've done as much as you can now. Get your boy back. Make sure he has his G3 qualification before he touches anything and get him to check it all over.

 

[nickelarsed]

Do you have a feed and expansion tank in the loft for your heating system?

 

[SafeGasInstall]

Must be something to do with Presure redusing valve ! Need to get plumber back to check Presure out of the balanced cold or hot water out let ? Also did they re bubble it up?

 

[PlumbBobBob]

possibly water pressure too high from mains as stan said get pressure reducing valve checked

 

[The OP]

possibly water pressure too high from mains as stan said get pressure reducing valve checked

Pressure reducing valve has been changed since all this kicked off (that was plumbers 1st guess). He even fitted a pressure gauge, but pressure never above 1.4 bar, even when noise is at its loudest. Heatrae Sadia engineer who claims noise is not coming from tank definitely regenerated the air gap. Still have the noise!

 

[The OP]

Do you have a feed and expansion tank in the loft for your heating system?

No- loft was converted, so just megaflo and a condensing boiler. No other tanks.

 

[The OP]

Have you checked that you neighbour isn't having any issues??

Not with noise, though I know for a while they couldn't get their water warm enough. all sorted now, but neighbours not sure what problem was or how remedied.