Baxi 552 - hubble bubble, only when I turn off

[Crystal Ken]

Hi,

I've got Baxi 552 backboiler. If I leave it on for say 2 hours or more, when I turn it off I get a lot of whooshing and bubbling running through the pipes. If I go in the airing cupboard then there's a cold pipe that goes to a t-joint, this pipe goes from ice cold to flipping hot, so I guess hot water is going up into the loft tank (I haven't been able to get up quickly enough to look). Previously it's done this and water came out of the overflow pipe...doesn't do that now though.

No banging though, just whooshing and bubbling.

The thermostat is on 3, if I turn it down to 2 then it stops doing this but then the radiators don't get hot enough.

Any ideas?

cheers

 

[Agile]

You need to inspect the F&E tank and get someone else to turn it off boiler while you watch it.

Tony

 

[Crystal Ken]

You need to inspect the F&E tank and get someone else to turn it off boiler while you watch it.

Tony

Thanks, what am I looking for? If water is coming out into that tank...what does it mean?

 

[Agile]

You need to look at the FAQs and see how an F&E tank should be configured and see what yours is like.

Then watch as the boiler turns off.

Also check what setting the pump is on. Normally "2" on a Grundfoss.

Tony

 

[Crystal Ken]

Why would it only do it at certain thermostat temperature settings? Wouldn't layout issues do it all of the time?

 

[Agile]

Different water temperatures, build up of air in parts of the system.

Many possible reasons.

But that's irrelevant as you need to find the cause and rectify it.

Tony

 

[Crystal Ken]

Ta

 

[Agile]

Take a sample of system water from a rad bleed point and see what colour it is.

Your fault may be causing more soon.

Tony

 

[simond]

You need to stp the thing pumping over or all your system will be ruined by corrosion. Or as Lemmy would have said, Killed by Death.