Central heating blockage ?? tearing my hair out

[susie w]

Hi Knowledgable guys out there- I have an ongoing central heating problem which seemed to start with our Baxi boiler going to overheat when the hot water was heating up. As soon as it got hot, over heat would come on.
The boiler has now been serviced and all looks good, new thermo sensor has been replaced just in case.

Seems that the return temphas been too hot- Sinc then we found that the water has been going back into the loft hot water tank! (there was a valve shut off and on opening that it now pumps out of an overflow into the garden each time.

We have had the system isolated - seperating upstairs off , that is now running well, we have heating and hot waterer. But we were getting no heat down the return pipe to downstairs radiators at all.

Pump has been replaced (was awfully gunked up and had metal bits in it too) radiators have been flushed out- loads of black water, still coming!

Plumber thinks next job is to take the floors up on the premiss that we have no hot water getting to the downsatirs radiators but upsatairs is ok.

Someone has said to me do NOT take the floors up- a return valve has gone and it needs replacing???
My plumber says we do not have one.............
Any help here would be marvellous indeed

Very frustrated in Taunton

 

[WHPES]

Firstly, is the pump working? If it isn't then you will only get heat upstairs.

Next check that the zone valve for downstairs is working (there is a manual lever on the side)

Next, if it is, if you shut all the upstairs radiators off does downstairs start to heat up?

If you were still getting black water then the system hasnt been flushed fully.

 

[Puddle]

Susie W reply sent via pm by mistake

Hi and thanks for your reply, Pump wasnt working properly- as bung was clogged with metal bits alowing only minimum flow- so replaced pump, and I believe the same gushing out of the overflow with water was still happening after this .
Diverter valve cleaned .
will check the downstairs zone lever as suggested- really dont want chap pulling floors up unless nec

 

[Boilerbud]

Make sure cold feed from expansion tank is not blocked, remove pump and open pump valve (obviously top one) water should come gushing out if not your cold feed is blocked. Magnet can sometimes locate blockage quite effectively.

Cheers

 

[< 0.004 = :-)]

can you check the pump hasn t been reversed (fitted wrong way round) when replaced. 'pumping over' - f&e tank overflowing after filling up from expansion and/or cold feed. can be caused by pump being fitted on the return .

 

[tamz]

Sometimes i really despair at the state of our trade.

 

[RoryD]

Susie W reply sent via pm by mistake

Hi and thanks for your reply, Pump wasnt working properly- as bung was clogged with metal bits alowing only minimum flow- so replaced pump, and I believe the same gushing out of the overflow with water was still happening after this .
Diverter valve cleaned .
will check the downstairs zone lever as suggested- really dont want chap pulling floors up unless nec

You have a blocked / restricted cold feed. You have intimated that you have sludge in your system, get it dosed up and flushed by a professional. Try and get it flushed by someone who will give a long guarantee i.e. who will come back and flush it for free in 5 years time should there be problems arising from sludge issues