Water not always hot

[hawklord]

A bit of advice please. My water heating is fine if we are at home and use the system everyday. The water heats up at the correct time and to the temperatire required. If we are away for a couple of days however we only have warm water on our return. Basically the water is not being heated up unless it is being used. Any ideas please?!

 

[Deleted member 120897]

It would be a good idea if you can tell us the system you have 1st.

 

[hawklord]

It would be a good idea if you can tell us the system you have 1st.

I have a Yplan gas boiler with storage tank.

 

[fowlerboi]

If you left your programmer on auto for hot water and heating set your room stat to 20 and cyl stat to 60 does it work fine?

If yes, if you then went away for 2 days without touching anything does it stay the same?

 

[hawklord]

If you left your programmer on auto for hot water and heating set your room stat to 20 and cyl stat to 60 does it work fine?

If yes, if you then went away for 2 days without touching anything does it stay the same?

It works fine apart from the hot water is very warm rather than hot. Start using the hot water and the next day it heats up fully.

 

[Basher]

A possible (contrived!) explanation - if your tank stat has developed a large hysteresis (difference between switch off and switch on temperatures), then maybe it doesn't click back on while you're away. When you're at home, running off hot water puts cold into the tank, the stat sees a large drop in temp and clicks in.
Only a thought, and only really relevant for a mechanical bimetallic stat! 🤔

 

[fowlerboi]

A possible (contrived!) explanation - if your tank stat has developed a large hysteresis (difference between switch off and switch on temperatures), then maybe it doesn't click back on while you're away. When you're at home, running off hot water puts cold into the tank, the stat sees a large drop in temp and clicks in.
Only a thought, and only really relevant for a mechanical bimetallic stat! 🤔

Yeah that has to be it. Hadn't even thought of that but makes a lot of sense.

Cyl stats are cheap as chips and easy to swap so its a good starting point

 

[hawklord]

A possible (contrived!) explanation - if your tank stat has developed a large hysteresis (difference between switch off and switch on temperatures), then maybe it doesn't click back on while you're away. When you're at home, running off hot water puts cold into the tank, the stat sees a large drop in temp and clicks in.
Only a thought, and only really relevant for a mechanical bimetallic stat! 🤔

Thanks Basher. That could well be a possibility. I might try that. 👍