oil combi boiler giving central heating but not hot water

[markmonty]

hi there i would be greatful if anyone can assisst mee, i have oil combi boiler which is giving central heating but no hot water,any suggestions as toi what to try first not to sure what to do with oil boilers as i do not have much experience working with them

 

[kimbo]

Need to know more, what make of boiler etc

 

[markmonty]

sorry im not to sure as iv not seen boiler yet ,i was thinking mabye a diverter valve but i dont know much about oil boilers,its for a family friend or i wouldnt touch the boiler

 

[kimbo]

Need to know what boiler, it could be a 3 port valve or a twin pump system or a hydraulic diverter valve.

 

[markmonty]

ok i will find out tommorow and send you a text ,thanks kimbo

 

[markmonty]

hi there the boiler is quite an old one and it says flowarm on it

 

[SimonG]

Not warmflow then?

 

[kimbo]

If it is a warmflow they work on a two pump system with non return valves in each exit port, if you are really unlucky they will have flexible hoses from the heat exchanger, these give problems and quite frequently block or collapse internally therefore not circulating the water through the heat exchange for hot water.

 

[markmonty]

ok thanks kimbo for your help much appreciated, and yes simon its a warmflow not a flowarm lol

 

[markmonty]

i have now seen the warmflow combi 70/90 , the both pumps are turning, heating works perfectly, however no hot water gets past the mixer valve above heat exchanger(i think the proper name for it is blending valve, when hot tap is turnrd on boiler fires up and heat exchanger gets warm upto but not past the mixer valve, the large red drum on the front of boiler which i think you call the expansion vessel is full of water is this normal or not, someone please help lol

 

[kimbo]

Sounds like blocked flexis, remove them and check for blockage

 

[markmonty]

is that the flexy which comes from heat exchanger, i think theres a 22mm one there somewhere, when i screwd the air valve cap off expansion vessell i got dirty black water is this normal . the drum seems heavy and full of water kimbo, thanks for the help i am hopeless when it comes to oil heating

 

[kimbo]

Yes the thats the flexi. Sounds like the expansion vessel has gone if its full of water.

 

[markmonty]

oki thanks very much for your help kimbo, much appreciated

 

[Best]

If, when you press the schrader valve on the expansion vessel, water keeps coming out, then vessel needs replaced. If not, then it may be okay if air charge is done using an air pump. This should have been part of a yearly service. Tell your friend to get an oil guy experienced in the boiler to give it a full repair & service.

 

[markmonty]

i think thats what il do ,the expansion vessell is definately full of water,when i srewd cap off it was dirty water that came out valve, i think the diaphgram is done, excuse my poor spelling