Hot Water Tank

[pauljoy]

Boiler was running for 45 minutes this morning, but hot water was nowhere near as hot as normal. Hot water tank was fairly hot at the top, but cold at the bottom. Is this normal or should whole tank be hot if no water is drawn from it?

Have a condensing boiler, Gloworm. Central heating is working fine. Thermostat on tank is set to correct temperature. Tank is at least 15-20 years old. Could sediment be forming at bottom of tank?

Any help please.

Thanks

 

[bster]

do you have any 2 port or a 3 port valve\s? Does your heating work alright?

 

[pauljoy]

Sorry bster, don't know what you mean by 2 or 3 port valves. I know there are 2 valves, 1 for heating and 1 for hot water, but not sure if this is what you mean. The heating valve was replaced last year. Hot water valve must be 20 years old.

Heating works fine.

 

[bster]

If it looks like this

http://www.h-i-e.co.uk/acatalog/zone.jpg

then id the one that is positioned on the pipe before it enters the hot water cylinder and turn hot water only on.

does the boiler stay alight?

does the pipe that runs between the valve and cylinder get hot (alot hotter than a period of say 15mins before you turned hot water ON)?

 

[pauljoy]

In answer to your questions bster, yes to all of them. Valve identified, Boiler stays alight
Pipe between valve and cylinder gets hot

I turned the hot water on 20 minutes earlier than central heating. Tank was hot from top to bottom, so that may be the answer.