No hot water except when using immersion heater

[bridgem22@googlemail]

I have a hot water cylinder heated by the boiler with an option to use it's immersion heater. When I use the immersion heater all is fine, but when I use the boiler only I don't get any hot water. The input/output pipes from the boiler at the bottom of the cylinder are both hot, and the hot water output pipe at the cylinder remains cold.

 

[tincup]

It would help to tell us more about your set up.
ie Does the boiler do heating and hot water. if so do the radiators get hot?
Is it open vented or closed vented

 

[Bod ...]

Photos would be good of tye cylinder cupboard with all the controls on show.

 

[bridgem22@googlemail]

See photos of config. I don't know if it is vented or not. The boiler does hot water and heating - I have just turned on a radiator and that worked fine. There is an immersion heater on the top and that works with my solar.

Hope this helps.

 

[tincup]

The pipe in photo 1 with the air vent.
Have you opened it a bit to release any trapped air?

 

[CBW]

It appears you have a 3 port mid position valve, I would investigate this. Perhaps try heating and hot water together and see if that works, if it’s does,it’s probably not going back to default position. I would also check the cylinder thermostat is set high enough.

 

[bridgem22@googlemail]

Thanks for everyone's help.

When I released the air vent then air came out and all is now fine. For info. I had solar installed this year and had not used gas to heat the water since April, so am guessing that the water in the pipe just stagnated(?) and caused air to accumulate somehow in the pipes through lack of activity. I may therefore have the same problem next year, so will vent the system in the same way.