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Andrew Smith
Andrew Smith, HVAC Technician
Category: HVAC
Satisfied Customers: 3768
Experience:  Heating and Controls engineer
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We have just had a Vokera Eccel 25 combi boiler fitted by a

Customer Question

We have just had a Vokera Eccel 25 combi boiler fitted by a registered plumber, the old system was a conventional boiler on a C plan. Prior to new boiler being fitted I replaced several radiators downstairs and one upstairs all of which got hot off the old boiler even though one of the new TRV's seems to be on the return rather than the flow. After the boiler was replaced one radiator in particular downstairs barely got warm, the plumber who fitted the new boiler suggested that I turn all radiators off to see if it would force heating around, I did this however it has now made it worse as both feed and return pipes are cold so needless to say so is the radiator. It has now been suggested by the boiler installer that we remove the TRV on this radiator as there is a larger radiator in the same room and is within 6 metres of this so will prevent the TRV working - does all this make sense and is there something apparent that seems wrong with possibly an easy(ish) fix?
Submitted: 3 years ago.
Category: HVAC
Expert:  Andrew Smith replied 3 years ago.
***** ***** : Firstly, does the radiator work if you take the TRV off?
JACUSTOMER-jmkpcqe7- :

No it still doesn't work.

JACUSTOMER-jmkpcqe7- :

I think that this is the worse £20.00 I have spent and feel ripped off!!

***** ***** : It looks like the pump is not powerful enough?
***** ***** : Can you turn all of the radiators off and then leave the head still off the radiator and let me know if it heats?
JACUSTOMER-jmkpcqe7- :

Tried that and it made it worse, what little bit of heat we had disappeared and the radiator remains cold, not even any heat in the flow pipe which comes from the room above.

***** ***** : I wonder if the pipework is wrong?
***** ***** : Has it ever worked properly?
***** ***** : Hi?
JACUSTOMER-jmkpcqe7- :

Yes all radiators worked fine until new boiler was fitted, could it be that the system has an air lock?

***** ***** : To see is it has then turn off one valve fully and bleed into a tub
***** ***** : Then do the other
***** ***** : You should be able to pull the hot water to the leg of the radiator on each valve.
***** ***** : Then turn both valves back on
***** ***** : If one leg gets hot and the other goes cold then you have circulation through the radiator
***** ***** : If they both stay hot and go grdually
***** ***** : gradually colder then you have no circulation through the radiator