hot water gravity slows to nothing

[Mark OD]

Hi,

My gravity fed hot water slows to nothing over 30 seconds. when tap turned off for 5 mins, tap will run again for 30 seconds etc.

I have tried the mixer tap/air lock trick about 10 times now and still not fixing.

I have drained the HW tank a little so I can inspect the 22mm out pipe at top of HW tank for scale etc: it is clear.

I do have a MagSafe but I'm guessing this is not an issue cause its on CH

I also have a shower pump, and I don't know if this could be a cause to my problem, which happens on all HW taps, upstairs and downstairs.

Thanks in advance for your advice

Mark

 

[Ben-gee]

Definitely sounds like an airlock.
Easiest is get a wet vac on the hot to the bath and keep sucking until the hose is thrashing around like an upset snake , then pull the vac away and hee water should continue from the tap at full force. Let it run for a bit. Then shut off , wait and Ghent turn back on - it should be fine but if not just repeat for longer.

 

[Last Plumber]

Have you checked the cold feed tank connector for blockage? As well as any gate valves in that run.