Barely any hot water flow

[Rich82]

The hot water in our house has recently lost all flow pressure. When I first turn the tap the water comes out with normal pressure then once it's warm the flow slows down to a trickle.
There is also a trickling sound coming from the pipes that lead to/from the cylinder when the tap is open.

It's a back boiler system, does anyone know what could be causing the slow flow.

Cheers.

 

[HERTS P&D]

Air lock.

1. Close all taps
2. Place your hand under the spout of the kitchen mixer tap.
3. Open hot tap and then open the cold tap very slowly (forcing cold mains water up the hot water side) Do this for about 30 seconds.
4. Close cold water and then remove your hand.
5. The hot water should flow as it should.

Or connect a hose pipe from the garden to the hot tap and force cold
water up the hot tap.

Or use a wet vac and suck the air out from the hot tap.

Hope that helps.

Just to let you know I was called out today to do this for a customer.

Andy

 

[Rich82]

Thanks for the reply, I will give that a try.

cheers.

 

[dcawkwell]

blockage from header tank to hot water tank

 

[Rich82]

I've tried the cold water pressure trick but has'nt changed anything. But I've noticed some brown deposits in the water now. Limescale build up?

 

[Boilerman2]

The top outlet could be scaled up restricting the bore of the outlet
switch off cold feed open downstairs hot tap untill water stops
disconnect top connection on cylinder use a large flat blade screw driver into the top fitting to see if any scale is present, you should be able to clear it with the screwdriver, refit top pipe connection and open up the cold feed finally test water flow

Here in my part of Suffolk water hardness is 450ppm and this is a common fault

 

[LockMonster]

My hot water gets slower and slower, till almost a stop, then fter about 15 - 30 secs full blast as normal, I changed the pressure vessel near the immersion storage, it had 3.5 bar which is fine. Still no good.