3-Port not switching to hot water. Advice needed please?!

[Wycherley86]

Could somebody give me some ideas as to what the problem with this 3-port valve is please?

A couple of days after i had drained down a customers system to repair some pipework (Y-plan, open vented) they are reporting that they no longer have hot water and the 3 port is not switching over to hot water when requested on programmer. There is a manual bleed on the flow to the coil with no air coming out. The cyclinder stat is set to 65.

I have spent alot of time on new installation work instead of problem solving so please excuse me if it is something fairly simple.


Many Thanks

Chris

 

[Ch4 plumbing]

You need to check if the valve is opening to hot water first, then you say no air comes out of the finger vent, what about water?
Does the cylinder have a l/s valve on it and did you close it to work on the system and did you open it again when you finished?

 

[BLOD]

What make/model valve is it ?

 

[Wycherley86]

Yes water is coming out. The hot water was working for a couple of days after the drain down and fix but now doesnt. Lockshield is open. Make is a Drayton, will have to come back with model. Thanks

 

[kay-jay]

is the valve energising on hw demand? if so i would say likely cause is airlocked coil after draindown

 

[Simon F]

more details needed.
is the boiler firing up on hot water only, but not heating the cylinder? heating the rads instead??
power for hot water is programmer-cylinder stat-boiler,
if there is no power then the problem is programmer/cylinder stat.

if there is power then its a circulation issue.
as said closed valve? airlock? or valve is stuck open to heating.

 

[Wycherley86]

All is sorted and working. Was an airlock in the coil i believe. Knocked off all power and set the three port to manual and then vented and got some air from the system.
Cheers for all your help and i will use all feedback to better diagnose a problem in future

 

[kay-jay]

Glad its all sorted mate.