Hot water coming on in between set programme on lp241

[Dave comber]

Hi there
My hot water is set on “once” on my lp241 timer between 4-5am which works perfectly.the problem I have is that the boiler kicks in randomly all day to heat the water.i have switched the central heating side of the timer down so I know it’s the hot water side kicking in.my last gas bill was £600 dearer than the year before so it’s obviously costing a fortune

 

[stem]

You don't give any information about the rest of your system, but much would depend what the lp241 is connected to and how it's controlling the system. It's possible that the lp241 is wired to a hot water cylinder thermostat and that controls a motorised valve which in turn controls the boiler. It's possible that a fault with the motorised valve could keep the system going. But your system may be may be different.

Alternatively the programmer may be faulty and the hot water is permanently 'on' even though the indicator light is switching 'on' and 'off' as normal. Has anything relating to the system been changed recently, or been disturbed, have any fuses blown?

This type of fault can be difficult to diagnose over a forum, usually it requires a physical examination of the system and tracing back the spurious 'live' with a multimeter to find its origin.

 

[Dave comber]

You don't give any information about the rest of your system, but much would depend what the lp241 is connected to and how it's controlling the system. It's possible that the lp241 is wired to a hot water cylinder thermostat and that controls a motorised valve which in turn controls the boiler. It's possible that a fault with the motorised valve could keep the system going. But your system may be may be different.

Alternatively the programmer may be faulty and the hot water is permanently 'on' even though the indicator light is switching 'on' and 'off' as normal. Has anything relating to the system been changed recently, or been disturbed, have any fuses blown?

This type of fault can be difficult to diagnose over a forum, usually it requires a physical examination of the system and tracing back the spurious 'live' with a multimeter to find its origin.

It is connected to a hot water cylinder so your explanation sounds right.il get it checked out.thanks for the information

 

[heatservice]

The once setting is also known as all day, comes ON at the first setting goes off on the last setting, eg on at 4am OFF at 10.30pm or whatever you have it set at, so once is more than twice a day. Try setting it to twice a day and change your PM settings to ON @ 4pm OFF@ 4:30pm and Im sure your boiler wont fire up outside those times.

 

[CWHEATING]

£600 dearer?! You may have a small gas leak. Get a qualified Gas safe engineer to come and test for leaks.