Do you know what make & model this is?

[uksparks]

Hi,

I don't suppose anyone knows what make and model this heating controller is do they?

the customer has just sent me the photo, I plan to swap it for a Honeywell 7 day programmer but need to know which way its wired really.

Thanks to anyone who knows!

 

[Leesparkykent]

Hi,

I don't suppose anyone knows what make and model this heating controller is do they?

the customer has just sent me the photo, I plan to swap it for a Honeywell 7 day programmer but need to know which way its wired really.

Thanks to anyone who knows!

View attachment 29327

If you take the programmer off it will more than likely have a wiring diagram on the back.

 

[uksparks]

Yes they usually do, I was just hoping to have a look on the net before hand really so that I don't have any surprises.

 

[Dave OCD]

Not sure but there's probably a wiring diagram on the back of the unit with a bit of luck, may even be the same or very similar 'industry standard' backplate.

 

[davesparks]

It's a two channel programmer, just replace it with a 2 channel programmer. The only thing that could be a little funky is if it's a gravity system, but then you just flip the switch on the back/move the jumper.

 

[Dave OCD]

If you take the programmer off it will more than likely have a wiring diagram on the back.

You beat me to it by seconds Lee. :icon12:

 

[Leesparkykent]

You beat me to it by seconds Lee. :icon12:

:ciappa: Lol

 

[uksparks]

I do t really touch heating controls, so you are going to have to explain how I know if it's a gravity system.

 

[jeremy]

I think a gravity system is fed from a header tank in the loft. I could have made that up though.

 

[Leesparkykent]

I do t really touch heating controls, so you are going to have to explain how I know if it's a gravity system.

I wouldn't worry about it to much. Take the programmer off and look at the back. If it doesn't have a diagram it will have a make/model you can google.

most programmers with industry standard back plates are like this.

 

[davesparks]

I do t really touch heating controls, so you are going to have to explain how I know if it's a gravity system.

If turning the CH cannot be turned on without the DHW being on then it is gravity.
In a gravity system the DHW channel on the programmer fires the boiler, the heat then gravitates through the pipework to heat the cylinder. The CH channel switches the supply to the roomstat which then operates a pump to circulate water in the heating pipes. Thus to have heating on the hot water must be be on.
The gravity setting on a programmer will prevent CH being switched on without DHW being on.

Other clues to a gravity system are the lack of any motorised valves or cylinder stat, an ancient boiler, 28mm (or bigger) pipes to the coil.

 

[davesparks]

I think a gravity system is fed from a header tank in the loft. I could have made that up though.

That's an open vented system which has a header tank at the highest point in the system.

 

[uksparks]

Thanks for your help, I'll pick up a 7 day Honeywell programmer and take it over.

thanks as always!

 

[jeremy]

I'll just keep quiet, and follow the rest of the post!!

 

[davesparks]

Any particular reason you want Honeywell?
If not I'd recommend Drayton over Honeywell. We'd normally fit an LP522 (5 day/2day, 2 channel) as standard or an LP722 (7 day, 2 channel) if the customer really wants 7 day control.
The vast majority of people just want the 5/2day option so that they have one set of times for weekdays and another for weekends.

 

[Leesparkykent]

Thanks for your help, I'll pick up a 7 day Honeywell programmer and take it over.

thanks as always!

If you get a Honeywell st9400 you will have to change the parameters on the programmer to mini programmer if it's gravity hot water.

http://www.honeywelluk.com/documents/Installation-Guide/pdf/835.pdf

enter installer mode, flick through to parameter number 7 and change the 0 to a 1, press ok and exit installer mode.

 

[davesparks]

I'll just keep quiet, and follow the rest of the post!!

There is a ridiculous amount of confusion among electricians about what the different types of heating system are and how they work. Personally I just don't understand why? It didn't take me long to ask a few questions and learn how they all work and how the controls should operate.
It baffles me that people call themselves electricians yet can't manage to join a few switches in series to control domestic heating, it's not exactly a complex control system! Just so long as you understand when and where safety stats need to be put in certain systems it can't really go wrong'

 

[Dave OCD]

I enjoy this sort of thing, it's a bit more interesting than the run of the mill stuff. The mess some people make of the wiring centre can be equally entertaining and frightening.

 

[alanl]

If it is gravity, then there are fewer programmers around now that are suitable for gravity systems.
A plumber asked me to fit one recently, a cheaper Drayton iirc, and it couldnt be configured for gravity, only fully pumped, so be aware of what system it is before buying.

 

[uksparks]

Any particular reason you want Honeywell?
If not I'd recommend Drayton over Honeywell. We'd normally fit an LP522 (5 day/2day, 2 channel) as standard or an LP722 (7 day, 2 channel) if the customer really wants 7 day control.
The vast majority of people just want the 5/2day option so that they have one set of times for weekdays and another for weekends.

I know the Honeywell ones, but by the sounds of it the Drayton one will be perhaps a better swap in this case.

I appreciate the help from everyone thanks!