Thorn Apollo no hot water....

[twgas]

I gree that it might be a pump problem - they often appear ok when are, in fact not. Does anything get hot (very hot) or does everything shut off before any real temperature is reached?

 

[picasso]

had another go today with the system,i didn't realise the central heating does not work as i have not had it on all summer.
When i put the heating on it cuts out after 3minutes the radiators get luke warm and then cuts off.i thought it could be the overheat stat on the boiler so i bypassed that but still cut off along with the gas valve this time.

you say the boiler fires up for 3 minutes and then cuts out, what makes you think its not the pump ?

 

[ALd2010]

yes thats correct the boiler fires up but cuts out after 3minutes the radiators seem to get luke warm and the pump seems to be running.
how does the boiler know to cut out if the pump is faulty is it linked to the pump overrun thermostat??
is there a way of checking that the fault is definitely the pump with changing it?

 

[looneyfitter]

Do the downstairs rads or the upstairs get warm? The pump motor could well be running but that doesnt mean the pump impellar is....

Sounds like either the pump or the boiler stat

 

[mysteryman]

There is a limit thermostat on these boilers, it cuts the pilot off if it overheats. This can be lack of circulation, airlock or whatever. Just because the pump is running does not mean that your circulation is OK. You should not bypass the limit thermostat.

 

[ALd2010]

both upstairs and downstairs rads got luke warm,i did not bypass the limit stat.the pump actually gets really hot after checking it again today is this normal?

 

[twgas]

i thought it could be the overheat stat on the boiler so i bypassed that

i did not bypass the limit stat

Limit and overheat are one and the same.
If the pump is significantly hotter than pipes, the pump is the most likely suspect. Do you get any serious banging in the pipes just before it all shuts down?

 

[ALd2010]

On the boiler i have the overheat cut off device is situated on the heat exchanger,and the the high low thermostat is behind the actual switch.but from the information you have told me it sounds like the pump is the problem.there is no sound of banging in the pipes though.
but will this sort the problem of when i put the boiler into hot water only mode? as this was the original problem.and i have been just using the immersion heater over the summer then recently found out the heating and hot water mode doesn't work either. i appreciate your reply's.

 

[looneyfitter]

Sounds like the pump defo to me matey.... Also check there is water in the system. Could be airlocked too