Rads getting hot when hw is called

[collyplumb]

Thanks sam. original was honewell so client got BG to replace but they changed to drayton. i thought (clutching straws ) this may have altered something so i fitted new honeywell. sort of cancelled out any incorrect wiring prob by fitting stopcock after 3port on CH flow and shut it to prevent any flow either way.

 

[gas4you]

Try taking the actuator off the 3 port valve and rotate the stub manually to each position and see if you can get the rads off like this.

 

[gas4you]

Check wiring from cyl stat is correct. Check cyl stat is working correctly?

 

[collyplumb]

Hmm i have not had a very close look at cyl stat wiring. it is working well though. ie. turn, click, on.. turn, click, off
?? thanks though for sticking with me with this

 

[gas4you]

Have you checked wiring/3 port valve installation is correctly installed to honeywell wiring diagram, of just copied BG valve replacement directions of flow and wiring which could have been done wrong

 

[collyplumb]

I copied theirs but did go over it a couple of times to make sure it added up.

 

[gas4you]

I would suggest starting from scratch and ignore their wiring. Its easy to mis interpret all those wires in the junction box

 

[collyplumb]

I think you may be right. I'll give it a go. pretty much exausted all else. thanks for the help dave. sam you to. thanks.

 

[namsag]

Right start with basics,, You say when just HW on and rads turned off at valves ,then turned on at valves they heat from lockshield side.

Is this the same when just heating is being called for or do they heat from trv side

Customers lie or better way of saying it get mixed up. It may always have done it , it may be teed in wrong..

From stone cold and all rad valves open just put HW on as the flow and return to cylinder get up to temp feel the CH flow to the rads from the 3 port valve about 18 inches away from valve if poss. If this is hot your valve or wiring is faulty if it is cool and your rads are warm there is a tee in the wrong place causing revere circulation

 

[collyplumb]

right. the rads are getting warm from alt ends. L/S when HW call. TRV when CH call. 18 inches away stays cold. so it points to reverse. cool. but i have shut all rads and drained CH flow down. drain still open and i have can blow air through ch flow side. all while HW circulation is on.

 

[namsag]

I f rads are heating up when just HW on and ch flow from 3 port valve is cool there is definetley a tee in the wrong place on the return. Finding it is the fun

 

[collyplumb]

OK but if this was the case then would water not continually run out the drain when only HW is circ with all the rads shut of. this would indicate the link.

 

[namsag]

No cause the tee is in the return and flows through the rads backward when HW ON you have turned off all the returns on the rads so water cant come through . All returns from rads should be joined together before joining return from cylinder and back to boiler in one tee .. One leg of tee from cylinder one leg from rads and one direct to boiler. SO one tee joins all returns back to boiler. There should be no other tee in return back to bolier ..What you seem to have is not all rads are joined together before tee and the return back to boiler has been teed into again