water not heating but rads hot

Riskymove

Hi

I have an oil central heating system.

while the rads get hot the water in the tank is not heating

can anyone suggest possible problems before I resort to getting plumber in?

thanks

Risky

Onikage

I had a similar problem. There was a small red tap on a pipe at the base of the immersion tank, once that was opened the water starting heating fine. Takes a long time to fill the tank that way though, about 4-5 hours as opposed to 45 mins using the electric element.

10-10-20

You may be able to install an automatic valve onto the pipework to divert the boiler output to the hot tank directly, reducing the heating time. Coupled with a timer, this can control either the residential heating or the hot water tank at different times. It's called zoning.

PaulieBoy

I presume that the water did heat up in a timely fashion at one stage and does not now ?

In which case you could try shutting down all the rads while the heating is on. It could be just an air lock in the coil in the cylinder.

Riskymove

Onikage wrote: »

I had a similar problem. There was a small red tap on a pipe at the base of the immersion tank, once that was opened the water starting heating fine. Takes a long time to fill the tank that way though, about 4-5 hours as opposed to 45 mins using the electric element.

thanks I presumed something like this but cannot find any tap

Riskymove

PaulieBoy wrote: »

I presume that the water did heat up in a timely fashion at one stage and does not now ?

In which case you could try shutting down all the rads while the heating is on. It could be just an air lock in the coil in the cylinder.

yep it did

I'll try this


yes this seems to be doing the trick thanks

Lex Luthor

the red hand valve may not be on the valve on the pipe mentioned.

look at the pipe coming out of the bottom of the immersion tank...

there should be a valve on this...open it a 1/4 turn using a pliers or check around inside your immersion closet on one of the other valves and pull off the red hand valve to use on this one and see if it improves

JamesM

If it worked up to recently and no valve was closed, it probably means that there is not enough water in the system. Either water is not coming down from the header tank, or a valve needs to be opened to fill the system.
Jim.