Drayton mid position valve staying warm/hot when heating/water not turned on

[JULIAN FALCONIO]

HI all
Hope someone can enlighten me on if I have a problem or not really.
I'm not a plumber but "like" to think I have a half decent amount of common sense?? lol
Immersion heater stopped working and mid position valve was seized at mum and Dads place so thought I would help out and have a go.give advance warning that the hot water tank could go....and sure enough it did lol
Changed tank/cylinder and complete valve and all works perfectly with no leaks,hot water kicks in when it should,valve switches between H..Mid and W as and when required......
Now for the head scratching part which I cant find a definate answer for.........when heating and water are off(as in not requested).....the valve electrical box remains quite warm even though pipes are cold , the valve position is in H....I'm guessing something is staying switched on but is this SUPPOSED to work like this???.... my thinking is if it does work like this somethings not gonna be working for very long
Any advice please......cheers

 

[ianmcd]

No when no demand the valve should go to W not H, you have not wired the HW off wire correctly, it should be connected to satisfied from the Cyl stat and HW off from the programmer

 

[D_Hailsham]

No when no demand the valve should go to W not H, you have not wired the HW off wire correctly, it should be connected to satisfied from the Cyl stat and HW off from the programmer

I have to disagree. If the valve is in the CH only position and CH is satisfied or turned off, then the valve will stay in the CH only position until either the power is turned off at the switch controlling the heating system, or there is a call for HW.

View media item 31084

 

[CBW]

So the last known call, eg heating, only stays in heating until satisfied? Then springs back after ch off at programmer?

 

[D_Hailsham]

So the last known call, eg heating, only stays in heating until satisfied? Then springs back after ch off at programmer?

Which post does this refer to? Here are all the options for a mid-position valve:

View media item 31085View media item 31084

 

[CBW]

Which post does this refer to?

This post, I was asking Ian, didn’t know you’d answered at the same time.

 

[terryplumb]

If everything is functioning as it should ,i.e boiler runs as it should for c/ heating and domestic hot water ,under the selected functions of the programmer ,then you would appear to have wired up correctly.
The 3 port valve will be warm ,and remain so ,under certain conditions even when the boiler is not operational and nothing calling for heat. Pretty much as laid out by D.Hailsham above.

 

[JULIAN FALCONIO]

Hi guys...thanks all for the replies...valve switches fine between all settings on demand or on timer....if water is last command it will stay on W and will be fine....if last call is for heat...it will stay on H and only then it seems to get warm.....even after half hour or so when pipes have cooled down....if that helps better to explain my brainteaser a bit better...have read MOST people say this is normal....but never noticed it on my own one at home....cheers guys

 

[JULIAN FALCONIO]

Sorry...me again....tank stat has been replaced to and cuts in and out fine as drained the tank a bit to make sure it was doing what it is supposed to do
(My dads water bill be a bit bigger this month lol)

 

[terryplumb]

Quite normal with Y plan set up. It will stay in that position , indefinitely, until the programmer / timer settings are changed. The motor will continue to draw a small amount of current during this mode ,hence the heat.

 

[JULIAN FALCONIO]

thanks terry...just got home and my one at home does same aswell.. so guessing all good...
just seems wierd to me that something should be left on when nothing required....amazed they last
as long as they do

 

[Hugh Jaleak]

I always advise people to set the timings to switch the CH off before the HW, which should encourage the valve to return to the 'Rest' position whenever possible. As said, the Valve will continue to draw a small amount of current to hold it in CH position even with CH off until it gets a command for HW and moves the valve again. In 'Rest' position the valve is sprung return to be open to HW only.