Drayton LP241 timers in a strange state

[Jon Weaver]

My CH/HW is controlled with a Drayton LP241 (Which is rebranded as Iflo as I replaced it a few years back due to a fault).

Its been fine for years but last weekend I 'boosted' the water and the boiler didn't fire.. I then looked (listened actually) to the programmer and it was acting strange...

Yesturday I remove it and set it up on a bench just to prove that it was acting strange and its the same... Let me try to explain the behavour.

So start with both CH and HW in timed mode but off.

1. Press HW (on) - Click
2. Press HW (off) - Click
3. Press (CW) (on) - No Click
4. Press HW (on) - Click
5. Press HW (off) - No click
6. Press (CW) (Off) - Click

it seems that the behavour of HW is "locked" to CH in some way.. HW will only work when CH is off.. But also, CH will only come on, when HW comes on. Its a very odd condition and this is new.. nothing has changed.. it worked perfectly before.

Today I went to a neighbours to check their original LP241 (just to confirm, I wasn't going mad) and it works as I expected (ie 2 independant channels) which turn on and off (click) when you press either the HW or CH buttons.

This stinks of software, rather than hardware and I wonder if anyone has seen anything like this before and has any thoughts as to how to fix it... Is there any kind of "factory reset" (I read you can press/hold SET and + but for me it doesn't reset anything).. I hjave even contemplated removing the internal battery to try and clear the condition.

Thanks in advance for any thoughts

Jon

 

[ShaunCorbs]

Could be an internal fault relay stuck open etc

Bench test it supply 240 to it and go through it

Eg have light bulbs for heating and hot water or use a multi meter

Warning things will be live so if you don't know what your doing don't do it

Most likely to be the prog at fault

 

[Jon Weaver]

Done exactly that.. But used a multi-meter to verify the voltages rather than bulbs.. And the behavior is as described above.

I can't see how its a stuck relay as the behavior is the same every time.. Its following a new logic pattern which is constant..

 

[Jon Weaver]

I have created a video to show the issue... Basically, when the CH is on, the HW relay does not click

 

[Jon Weaver]

I have made an observation regarding the jumper.. If I move it to "G" the behavior changes and both HW and CH come on together, so I know moving the jumper does something

But if I take the jumper off, it behaves in the same way as it does in 'P' mode.. So i am starting to think that there is a hardware fault and its simply not detecting the jumper...

 

[ShaunCorbs]

jumper sets it to single channel

 

[Murdoch]

Buy a new one, they do go wrong, but easy to fit a new one ...

 

[Jon Weaver]

Buy a new one, they do go wrong, but easy to fit a new one .

Exactly what I am in the process of doing.. But just wanted to be 100% sure mine was actually faulty first..