potterton combi 80 no heating downstairs

[pet123]

Help please, I have a potterton combi 80 boiler thats 5 years old, about 2 weeks ago the heating downstairs suddenly stopped working even though it works upstairs and I also have hot water.

I was informed that the cause would be the pump which i have since got replaced but im still having the same problem.

when the boiler turns on however it will only heat up for a few minutes no matter what the thermostat is set at before it turns off again i have got heating upto 15 degrees upstairs, red hot water upstairs and downstairs but no heating at all downstairs.

I would be grateful if anybody could help me.

 

[alan m 1974]

Try turning rads that work off and see if it pushes heat through

 

[pet123]

I have tried turning upstairs off and left downstairs on, i have also bleed all radiators but found no trapped air but warm water will come out from downstairs when i bleed them

 

[alan m 1974]

If you want go to every rad and close both ends off,then fire c/h up and go to a rad that didnt work and open trv end fully,then l/shield end open just enough so the rad heats up,and leave as it is,go to next rad,and do the same,just balancing the system,check pressure is around 1 1/2

 

[alan m 1974]

is pump on right way

 

[alan m 1974]

Sounds like circulation,any work done on pipework recently,any new valves fitted

 

[pet123]

whats trv end and i/shield?
the pump is on right way and working properly.

 

[pet123]

no pipework done recently only new pump fitted but problem remains the same

 

[alan m 1974]

TRV ,THERMOSTATIC RAD VALVE AND L/S, LOCKSHIELD VALVE WHICH SHOULD HAVE WHITE CAP ON AND YOU CAN TURN THE ACTUAL WHITE TOP OR TAKE IT OFF AND WITH A SPANNER TURN THE VALVE OFF,TRV TURN TO ZERO OR FROST SETTING

 

[pet123]

tried doing one radiator but boiler not staying on long enough to heat up its turning off after a minute

 

[sooey]

It'll be either the diverter valve motor or the pcb I reckon. As long as your pumps alright like you say, and assuming that your heat exchanger isn't blocked.

 

[pet123]

how do i work out which it is

 

[The Baker]

Who changed the pump,

and,

how much of it was changed, or perhaps that would be better put by my asking, how long did it take.

Tim

 

[pet123]

the pump head was changed by a friend who said the pump was the problem, didnt take him long though. the pump is a myson cp63

 

[The Baker]

So its a Combi 80 so the pump is contained within the boiler case.

Has your friend has changed what I would call the the pump head rather than the complete pump?

Tim


PS, have re-read your first post and would like to know if the appliance was showing any signs of not working correctly whilst supplying hot water prior to the cold rads down stairs bit became apparent?