Drayton LP241 in a strange state

[jweaver]

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

 

[ianmcd]

sounds like your programmes is set to gravity HW and your neighbours is fully pumped there will be a slide or a jumper peg at the back of the programmer check what that is set to, if it is set correctly hold the SET and + buttoms for 5 seconds or untill the display goes blank and it will reset to factory default (wont affect the gravity/fully pumped settings though, you have to set tha manually

 

[jweaver]

So that makes sense.. Except the programmer has worked perfectly for years (where each 'channel' would react individually).. And suddenly, without warning, started to behave like this.

But whilst it was on the bench, I played with the 2 jumpers just in case (there is a 3rd, labelled 1 & 7 (which I believe to relate to daily/weekly program) but it does not have the jumper soldered to the board).

Neither of these jumpers had any effect on how my programmer re-acts. The entire logic of the device has changed, which is why this feels like a software glitch.

Jon

Edit: Just checked to be sure and my jumper is on P, not G.

 

[jweaver]

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

 

[jweaver]

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...

 

[ianmcd]

On G the HW/CH do come on together so the jumper is being detected

 

[screech]

Turn the hot water on, if you don't hear a click tap the top of the programmer with a screwdriver handle, use a little bit of force. If it then comes on its a sticky relay. When you turn hot water off you should heat a click to show that the relay had moved.

These clocks getting a sticky relay is very common.

 

[jweaver]

Turn the hot water on, if you don't hear a click tap the top of the programmer with a screwdriver handle, use a little bit of force. If it then comes on its a sticky relay. When you turn hot water off you should heat a click to show that the relay had moved.

These clocks getting a sticky relay is very common.

I don't think its a sticky relay.. If I put it in G mode (so both CH and HW are connected), when I turn on/off, I can hear BOTH relays clicking...

There was a slight development.. After many hours of playing (including a total disassemble) I took it to work to show a colleage.. And in work, it was fine.. This got me thinking that the "journey" to work some how unlodges something (Adding weight to your sticky relay theory).. But when I got home and tested again, the same fault had returned.

The ONLY thing different was the mains.. So I took it in again yesterday and the fault is still there.

I have concluded that its a fault.. And managed to find a local replacement on eBay for £5.. It was sold as 'for spares' as the guy had swapped it out for a fault which turned out not to be the programmer.. But when I got there, it was brand new.. Literally.. Not a mark on it.. No-way it had ever been used.. So I am in a good place now, as I have a brand new LP241 (rather than the 2nd hand Iflo I had before) and it working perfectly.

Thanks all for your help

Jon