Indirect cylinder heating problems

[Hugh Hair]

Boiler has 28mm pipes to indirect cylinder gravity feed. Pipe exit from boiler is hot (boiler stat no5). Hot water cylinder not hot enough, boiler running 24 hours continuously. Problem only started, previously piping hot. Can only think there is a blockage or restriction in pipe work, but seems unusual in large bore copper. Any ideas?

 

[Darren Jackson]

Thermostat on boiler been turned down or faulty?

Thermostat on cylinder Faulty?

Blocked feed pipe from header tank?

 

[townfanjon]

Have you drained the system down ?

Header tank 1/3 full of water ?

 

[Best]

Things that need checked are, -
Is there a few inches water in expansion and feed tank?
Is there water at top connection to coil?
Is there a blockage in the feed pipe?

 

[jtsplumbing]

As B4 small tank in loft is empty and water level in pipes is to low to let it gravitate

 

[Hugh Hair]

Thermostat on boiler been turned down or faulty?

Thermostat on cylinder Faulty?

Blocked feed pipe from header tank?[/QUOT

 

[Hugh Hair]

Many thanks guys, header tank empty. Filled up ok but will probably fit new ballcock. Problem solved, thanks a million
Hugh

 

[Best]

The older ballvalves that have brass pistons inside them will tend to seize up easily on heating tanks, as the valve rarely needs to replenish water

 

[quality]

The older ballvalves that have brass pistons inside them will tend to seize up easily on heating tanks, as the valve rarely needs to replenish water

I agree entirely, whats better to fit is a modern foreign valve that will fail and never shut off after a couple of years, that way it will need replacing again lol

 

[spanner]

Check emitters are all okay might need a tweek of a bleed after topping up the f&e.