Hot water not shutting off

[marks97]

Hi.

I have searched around but not found an answer to my problem.

My boiler seems to be always firing for the hot water even though I have turned the hot water off on the programmer.

We have a condensing combi Ideal Logic Heat 15 boiler controlled with a Drayton LP241 programmer. The boiler heats a massive tank on the top floor.

It is set usually to heat the water during set times and has worked fine until recently. Now even with the hot water turned off on the programmer the water keeps heating.

I have tried replacing the LP241 with another brand new one expecting that to fix the problem but it is still heating regardless. Any help?

Thanks

Mark

 

[JBPHS]

First of all your heat only boiler is not a combination boiler. Sorry to be the one to break the news.

Usually when this happens it's a sticking motorised valve (could obviously be something else). Do you know what your motorised valve(s) look like?

James.

 

[JBPHS]

And shall we diagnose the situation before random part swapping?

James.

 

[marks97]

First of all your heat only boiler is not a combination boiler. Sorry to be the one to break the news.

Usually when this happens it's a sticking motorised valve (could obviously be something else). Do you know what your motorised valve(s) look like?

James.

No worries. I was just told it was a condensing boiler when I moved into the house. I don't mind what it is as long as it works.

I know what the motorised valve is and where it is. What would you like me to check?

Thanks very much for your help.

 

[JBPHS]

Usually the motorised valve has a lever (used for manual override). With no demand for hot water, check the lever to see if it moves freely if at all. Whilst you at the the valve, if you can, take a photo of it and post it on here.

FYI a the boiler you have is a condensing boiler (usually identified by a plastic white pipe exiting the bottom of the boiler) but not a combination boiler (combi boilers produce heating and hot water directly from the appliance).

James.

 

[marks97]

Usually the motorised valve has a lever (used for manual override). With no demand for hot water, check the lever to see if it moves freely if at all. Whilst you at the the valve, if you can, take a photo of it and post it on here.

FYI a the boiler you have is a condensing boiler (usually identified by a plastic white pipe exiting the bottom of the boiler) but not a combination boiler (combi boilers produce heating and hot water directly from the appliance).

James.

Valve moves freely. Very freely like it is doing nothing. Its a honeywell 272848. Just working out how to add pictures now.

 

[marks97]

Untitled

• marks97
• 17 Sep 2014
• 1

 

[JBPHS]

The valve is stuck in the open position. What I do when faced with this is isolate the electrical supply to the heating. Test that the supply is isolated. Remove the valve head cover (tiny screw at opposite end of lever). I then remove the motor head from the valve body (x2 screws). If you are unlucky, the motor head will open up the water circuit. By slackening the two screws and moving the motorised head, if safe, you will find that the brass mounting plate will not move. If you've removed the head, check the spindle on the valve body. If this moves freely, the motor will need changing. If it doesn't move the whole valve needs changing.

To refit, place lever in 'MAN' position and refit in reverse.

James.

 

[marks97]

The valve is stuck in the open position. What I do when faced with this is isolate the electrical supply to the heating. Test that the supply is isolated. Remove the valve head cover (tiny screw at opposite end of lever). I then remove the motor head from the valve body (x2 screws). If you are unlucky, the motor head will open up the water circuit. By slackening the two screws and moving the motorised head, if safe, you will find that the brass mounting plate will not move. If you've removed the head, check the spindle on the valve body. If this moves freely, the motor will need changing. If it doesn't move the whole valve needs changing.

To refit, place lever in 'MAN' position and refit in reverse.

James.

Thanks so much for your help with this. I won't make the mistake of guessing the problem again.