Yplan switching problems

[Rotunda82]

We recently upgraded a gravity hot water system to fully pumped with an ACL Y plan pack but also using a Honeywell mid position valve ( dont know why - when I had got there one of the lads had decided to mix and match the packs - not that it should matter which valve is used ) - What we can't figure out is that now with the standard twin channel programmer the heating wont come on until the hot water is switched on ? Now they should work independantly and when using the ACL mid position valve in the past we get independant control so what difference would having a Honeywell valve make ? We had the sparky check all the wiring and he thought maybe a faulty programmer or head and as we had both on the vans we tried but to no avail ?

Any ideas ?
Cheers lads

 

[gas4you]

Is the h/w off terminal connected from the programmer correctly? Not all sparkies fully understand heating electrics however good they may be a general electrics for some reason

 

[Rotunda82]

Is the h/w off terminal connected from the programmer correctly? Not all sparkies fully understand heating electrics however good they may be a general electrics for some reason

Too true
Yes there was two of us there in the end and the sparky ( had to keep an eye on him though !! ) checking all of the connections - it just doesn't make sense - have you come across anything similar ?

 

[Mr Smyth]

This is the first thing that springs to mind

Check the position of the pins on the rear of the programmer.
Check the installation instructions of the programmer in question but on the ones I use the position of the pins/links you make the programmer suitable for Pumped/Gravity, Independent or linked times and 7 or 5+2 Day Timer.

Hope this helps

Mr Smyth

 

[Rotunda82]

Nipped back round today and checked pins etc.. still no joy

H/W only works fine cutting on and of with cylinder stat
H/W and Heating - both coming on and off independantly with stats as they should
Heating only - nothing ??

Any more ideas

 

[stem]

I agree with gas4you. It's easy to check as follows:

Check for a live supply on the grey wire to the motorised valve when heating only is selected, the live for the grey wire should come from the H/W off terminal of the programmer. This grey wire is the supply responsible for operating the boiler when the hot water is switched off or up to temperature.

If the grey's not live, check the HW off connection at the programmer. Also, has anyone blown the fuse at any point during installation? if so, sometimes this can blow a track on the printed circuit board in the programmer and you could have lost the HW off connection.

If grey wire at the motorised valve is live, is it switched through to the orange wire. if not the microswitch inside the valve is probably faulty.

When you say

"H/W and Heating - both coming on and off independently with stats as they should"

Does that include the heating working with the system set as follows:

Hot water on at the programmer and off at cylinder thermostat, and central heating on at programmer and on at room thermostat?

If this scenario is working, the grey gets a live from the changeover contact in the cylinder stat and would show that the valve is working.

 

[Rotunda82]

:

Hot water on at the programmer and off at cylinder thermostat, and central heating on at programmer and on at room thermostat?

If this scenario is working, the grey gets a live from the changeover contact in the cylinder stat and would show that the valve is working.

Yes sorry my wording should have been clearer - The heating works with the above scenario

What i'm trying to say is that unless the Hot water is selected on the programmer ( wether satisfied or not at the cylinder stat ) the heating will not fire when the room thermostat is turned up - Whereas normally I thought that you could turn on the heating without selecting the Hot water on the programmer ?

Am I making sense ?

 

[stem]

Yep makes sense. That proves the valve is working. So, I still think the problem is that you don't have a live supply to the motorised valve grey wire when the hot water is off.

 

[Johnny B]

This might help

 

[Dan Robinson]

You'd hope he'd have fixed it after 12 years.