three port valve packed up????? brrr its cold!!!

[Thermo]

Hi, after a bit of help guys.
ive got a potterton floor mounted old fashioned, boiler, pumped system with header tank in the roof, and a three port valve. just gone to turn on the heating and nothing has happened. the room stat is fully up and ive heard the click as it passes the temperature, no air lock as ive checked the rads and given them a quick bleed. when i put the water on the boiler kicks in and the system works and the pumps going. looked at the port valve and its permanently on the W setting. if i flick it across using the manual arm it fires up the boiler for the heating and then just shoots staright back across to the w setting. Even if i put it on M it still wont fire up. So in summary i know the boiler works ok so is the 3 port valve stuck?

Quick answers would really be appreciated

Thermo

 

[Thermo]

right think ive cracked it but just need to check.

i think ive narrowed it down to the port valve motor. Ive taken the motor off of the valve and when the valve arm is pushed across to the h setting with the room stat turned up the heating kicks in. When i do the same with the roomstat turned down low it doesnt. The motor does absolutley nothing. This makes me think the following
1:- the roomstat is working as its sendinga demand signal when its turned up
2:- the boiler is working as it fires up when asked to
3:- the actual valves arent stuck as the heating works when i jam it open

therefore it must be the bloody motor!

 

[shaggy]

Sounds like it and £8 from Screwfix. Wickes used to stock them but I'm not sure now. If you lock valve in mid-posn you will get heat to rads while tank stat is asking for heat.

 

[kevplumb]

if you take the head off and turn the spindle it wont return you will get heat
warm the cyl on mid pos then move the valve to ch and turn the stat up

not ideal but it stops your n*ts falling off

 

[Thermo]

cheers chaps managed to do that, got a small thingy holding it in the right position. The chap in tp said oh no comes as a complete unit. get it home and find it easily detaches from the valves. So if i can manage to undo the brass screws holding the motor housing to the vavle assembly can i just sawp the motors over or am i have to go through the process of draining it all down to replace the valve at the same time?

 

[keego]

It depends on what type of valve it is, the older honeywells & I think the older Landis require a drain down. Newer honeywells do not need draining.

 

[Thermo]

well i suppose theres nothing to lose by trying to take the motor assembly off first, i assume the valves should be in a closed position when powered down, sods law says ill end up draining it all down. Bang goes another saturday!

 

[kevplumb]

if it is the old honeywell you might get wet

 

[keego]

Draining down should not be to big a job if the valve is upstairs,you will only need to drain a bit off instead of the whole system.

 

[Thermo]

its an acl drayton, which looks remarkably similar to the one i was sold to replace it which is an ikon

 

[keego]

if it is the old honeywell you might get wet

Yes I have that particular T shirt.

 

[shaggy]

That was a good tip from Kev, I didn't know that one. If you've got a new motor there is no need to take the head off though, so no need to drain down even if it's the older non-sealed valve.

 

[Thermo]

yes youre right draining it off its not a big job if its upstairs. I live in a bungalow...oh well!!!

 

[Thermo]

chaps,
just a quick note to say thanks for your help. Changed the motor (5 mins flat oh great no mess hooray) and that didnt help as it still couldnt get far enough over to fire for ch, so i changed the lot and its working a treat (a little bit longer, but my missus knows some new swear words now, oh and even longer trying to bleed the system down, followed by constant nags of can i use the airing cupboard yet?)

cheers again

Thermo

 

[kevplumb]

now you know why we groan mate