Hot Water Tank

1 Dec 2005
Reaction score
United Kingdom
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.

Sponsored Links
do you have any 2 port or a 3 port valve\s? Does your heating work alright?
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.
If it looks like this

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)?
Sponsored Links
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.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local