Help!! Radiators hot but no Hot Water!!

[SallyC]

Hi there

I have a gas central heating system with Baxi boiler. The whole system hadn't been working for some time, the problem was the system kept shutting off soon after starting. I bleed the radiators, pump and reduced the temperature on the cylinder thermostat and the boiler appears to be working fine without shut of, the radiators are hot and the system is coming on and off satisfactory in accordance with the clock. I continue however not to have hot water and don't know what else to try.

Any suggestions will be greatly appreciated please??

 

[seco services]

have you one of these ?

or two of these near the pump ?

 

[SallyC]

Yes I do, the top one I think, though the box is turned the other way up.

Also the pipes are all hot up to that point then turn cold from there to the cylinder. Is there something I can do to that fitting then?

 

[seco services]

what did you set the cylinder stat to ?

 

[SallyC]

its at around 65, as it was at the maximum. I reset it yesterday

 

[seco services]

with only the hot water on at the programmer turn the cyl stat up does the boiler kick in ?

 

[SallyC]

yes it does, boiler works fine on both settings, hot water does not come out of the taps though. The pipes in the airing cupboard are hot right up to the part of the pic you posted, their is a pipe running from their to the cylinder which is cold.

 

[seco services]

so you turned the cylinder stat up and boiler kicked in but the pipe from valve to cylinder still cold ?

how long is boiler running for ? or does it cut out after a min or so ?

 

[SallyC]

I didnt need to turn the stat up, the boiler is running fine whether switched to heating, water or both. It seems to be running perfectly and not cutting out as it was before.

Yes the pipe remains cold, though all the pipes running up to the valve are hot.

 

[seco services]

have you got a bleed valve on the pipe from the valve to the cylinder ?

 

[SallyC]

I have no idea, what would it look like please, Ill have a look.

 

[seco services]

a short lenght of pipe vertical off the pipe from valve to cylinder
with maybe a thumb screw vent on the top

 

[SallyC]

Nope just looked, there is nothing at all on that pipe to the cylinder, just a plain pipe.

 

[seco services]

sounds like the cylinder coil is airlocked.

are you running the hw only at the moment no heating on ?

 

[SallyC]

Yes trying it now, what else shall I do?