CH & HW question.

Could someone in the group answer this question as to whether my CH system is correctly wired. To my mind it isn't:-

Its an oil fired boiler, fully pumped with a motorised 3 position (HW, CH & Both) 5 wire motorised valve, HW cylinder stat and room stat. And a 2 channel programmer.

With the programmer calling for CH and HW the 3port valve settles at the both position and the boiler runs. This is all fine. However if then the HW cylinder reaches 'stat temperature the whole lot cuts out. To my mind in this condition the 3 port valve ought to move to the CH position and the boiler relight until such time that the HW cylinder stat again calls for heat.

Is this correct or not? If not, how do I correct it, and if it is correct, can I mod it to work as I desire??

Cheers

Tim..

Reply to
Tim..
Loading thread data ...

No, this is NOT correct! For this system to work, the programmer must have live feeds for both HW required and HW *not* required - and the cylinder stat must be the change-over type - with a common plus either/or contact. My guess is that either or both of these (most likely the cyl stat) are wrong.

See the Y-plan details in

formatting link
work out how it should be wired.

HTH, Roger

Reply to
Roger Mills

My system is doing exactly the same as Tim's. AS soon as the HW gets to temp off goes the boiler :-(.

THanks to someone here last week who pointed me towards where to get info on my controller I got the specs from Potterton a few days ago. Diagrams didn't make any sense, whereas the Y plan diagram in th eabove link looks alot easier to follow. However, I can't see both our systems both being incorrectly wired so I'm going with some other fault.

HW alone kicks on and off correctly CH alone kicks on and off correctly

both together ...... :-(

John

Reply to
Wdyw

Check the wiring and make sure that it looks like the Y-plan diagram in

formatting link
the wiring is correct, but it still doesn't work properly, the likely culprit is a duff microswitch inside the 3-port valve's actuator.

Roger

Reply to
Roger Mills

will do ...there are two microswitches inside my magic box ..and while I can see they operate fine when you move the manual lever on the back of the box I can't for the life of me see how any electrical signal to them alters their state.

What should happen when the HW gets to temp?

Is it:

1/ Boiler knocks off 2/ signal to 3-way valve to move to CH only 3/ Valve moves to new position 4/ boiler signalled to fire up again

John

Reply to
Wdyw

In message , Wdyw writes

What actuator head does "he" have?

Reply to
geoff

Is

formatting link
help?

-- Adam

snipped-for-privacy@blueyonder.co.uk

Reply to
ARWadsworth

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.