No hot water flow

[technomole]

Afternoon.
I have an issue with no water flow from any of the hot taps in the house, I can't seem to find a solution to the issue.
System is a megaflo unvented indirect cylinder (125i) boiler is a Worcester greenstar.

I have good pressure on the cold feed and all the usual stuff works, taps, toilet, shower (electric not fed from cylinder)
just no flow from the hot.

I recharged the air gap in the cylinder as per the instructions on the cylinder, but now the t/prv won't open, it just clicks
and I've checked the pressure reducing valve, it seems to be fine, cleaned the filter.

I though it could be an airlock, but it seems this is unlikely as these systems very rarely get airlocks.
The heating works, and the 2 port valves seem to be okay, they energise and work as intended

I'd appreciate any other ideas as at the moment I have no hot water (as in you can turn the tap on and nothing comes out)

Many thanks.

 

[ShaunCorbs]

Check the blue handle valve is open and the handle isn’t just spinning eg with the hot tap open you should hear water rush into the cylinder when opening said valve

I’m guessing you closed it to re charge the air gap ?

 

[technomole]

Check the blue handle valve is open and the handle isn’t just spinning eg with the hot tap open you should hear water rush into the cylinder when opening said valve

I’m guessing you closed it to re charge the air gap ?

Yes I shut off the cold feed to the cylinder, valve just before the pressure reducing valve, no sound of water when opening / closing the valve with the hot tap open.

 

[ShaunCorbs]

Yes I shut off the cold feed to the cylinder, valve just before the pressure reducing valve, no sound of water when opening / closing the valve with the hot tap open.

Is it a stop tap eg like your mains or the blue plastic type ?

 

[technomole]

I've attached a picture, water feed is from loft, goes into a scale filter, then to the valve (blue plastic handle) then to the pressure reducing valve, the 22mm to 15mm 'T' fitting goes to the filling loop, and the grey insulated pipe comes out of the top of the cylinder and I believe this is the hot water feed.

 

[ShaunCorbs]

Water at the filling loop ?

 

[technomole]

Water at the filling loop ?

Yes, water to filling loop is okay, and pressure is good.

 

[ShaunCorbs]

So valve or prv faulty need a g3 engineer sorry to say

 

[technomole]

So valve or prv faulty need a g3 engineer sorry to say

Okay, thanks for the advice.

 

[technomole]

Just thought I'd post this update, I've had a heating engineer out and he fixed the issue in about 10 minutes, basically whats happened is that on the bottom of the pressure reducing cartridge there is a small plastic cap (dome shaped) I took the cartridge out to clean the mesh, but never noticed the cap wasn't there.
The cap had found it's way into the pressure relief valve and basically blocked it, I've attached an image of the base of a PRV just in case it helps someone else out, the engineer said in 23 years of working on similar systems he's seen this happen about 12 times.

 

[Ben-gee]

Thanks for update.
Did the engineer re-attach the white plastic dome - or simply remove it?

 

[technomole]

Thanks for update.
Did the engineer re-attach the white plastic dome - or simply remove it?

Morning, he took it out from where it was wedged, it's currently not attached and the system is working, not sure what effect it not being on there will have, after looking online for spares and such like it seems a lot of the pressure reducing valves don't have them on anyway.