Drayton LP522 not working

[Mole Catcher]

Hi everyone,

Our local young electrician put in the LP522.
At the time he mentioned that there were far more wires all red then he was expecting but carried on.

To start with if we pressed the hot water boost boiler would fire up. But after quite a delay up to 2 minutes
Because of the cold weather thought we should try the advanced CH but would not fire up.
Now we can only get hot water by turning the thermostat up, the control panel no button pressed, but CH comes on as well, as if the thermostat bypass the control panel.

Any ideas to pass on to the electrician?

Photo of the wiring

Thanks for your help

Chris

 

[RandomGrinch]

Our local young electrician put in the LP522.
At the time he mentioned that there were far more wires all red then he was expecting but carried on.

I think you need to get him back.

There seems to be problems here, that makes remote diagnosis over the internet quite difficult!

Without looking too deeply, there appears to be a wire link between L and terminal one - The dual channel LP522 has internal links, making this wire unnecessary and incorrect. In this case it seems to be providing a permanent live to Hot water off.
There also appears to be a wire into terminal 2, C/H off - this is a connection that is rarely ever used, I doubt this wire should go here.

I hope he has taken a photo of how the wires were connected to the previous controller - if you can get hold of the photos, and let us know what model the controller was, we might gain an understanding of how he went wrong.

 

[Mole Catcher]

Thanks for the reply, unfortunately he said tonight when he popped back that he really should have stopped but if you don't try you don't learn, ( there is a little logic there) but I like to take photos of everything before and during any task, but unfortunately he has not.
But will pass on your comments to see what can be done.
Thanks

 

[RandomGrinch]

Do you know what type of system you have?
Is it an old gravity system?
And what was the previous controller?

If you know what you have, we may be able to push him in the right direction!

 

[Mole Catcher]

Hi,

Thanks for the reply.
Gravity fed
The old unit was a letter H with a little dot and 525.

Horstmamn or Hosemann something like that
Will do some more digging to see what is is

Thank you for taking the trouble to help

Chris

 

[Mole Catcher]

If you zoom in can see old control panel

 

[RandomGrinch]

The old unit was a letter H with a little dot and 525.

Your old controller was a Horstmann 525.
As I suspected (and why I asked about your previous controller), the Horstmann has extra terminals...

Hence the need for separate link wires between terminals L, 2 and 5.
Your electrician has tried to incorporate these links, that aren't necessary on the LP522...

So the first thing to do, is to remove any superfluous links!

The LP522 should also be set to gravity mode..

Is there any chance of a better image of the LP522 wiring?

 

[Mole Catcher]

Some hopefully better photos and one of the back of the panel in case these are wrong?

 

[Mole Catcher]

 

[RandomGrinch]

Some hopefully better photos and one of the back of the panel in case these are wrong?
View attachment 356105

Thanks for the photos, I'm afraid I can't tell much more.

As you said at the beginning, you suspect the thermostat bypasses the controller and there appears to be four cables attached to the backplate; I believe the thermostat cable is also terminated there.

A gravity system wired to your old controller may look something like one of these...

This is guesswork, but It is possible that the thermostat cable had a red live wire connected to Horstmann terminal 4 (leading to the thermostat) and a black switched live coming back from the stat - this black wire would then need a separate joint to the pump live on one of the other cables (it wouldn't be connected to one of the controllers terminals).
If this is the case, it should be relatively simple for your electrician to work out, using his test kit.

If you could post a photo of the wiring behind the stat, this may give us a clue, but we're pushing the limits of what I can deduce!

...and yes, it looks like the LP522 is set to Fully Pumped instead of Gravity.