Problem with hot water pressure - Conventional Boiler?

[wilkinson_rober]

I live in a top floor flat with two bathrooms and what I think is a conventional boiler (large tank in the airing cupboard, feeder tank above it, but with a small British Gas unit in the kitchen (if fires up when the hot water/heating is turned on). We moved in in August 2010 and the hot water and central heating worked fine. Over the last few weeks, the water pressure in respect of the hot water has slowly dropped to the point that it now takes 30-40 minutes for any water to come out of the hot water taps once they are turned on. Eventually we get full hot water working through taps and shower, and at normal pressure but it is taking 30-40 minutes.

The only thing I've done during this time which I believe may have an effect is to bleed the radiators in the house. But even after this was done the pressure was still sufficient to provide hot water within a minute of turning the taps on. I have checked the pressure gauge by the water tank which is currently between 1 and 2.

I have no idea what the cause is or how to resolve it, but am reluctant to pay for a plumber if its relatively straightforward. It seems strange that this pressure drop has happened seemingly a couple of weeks after bleeding the radiators, but it could just be coincidence. Any suggestions gratefully received!!

 

[Plumbstar Tom]

it now takes 30-40 minutes for any water to come out of the hot water taps once they are turned on.

so when you turn the hot water tap on nothing at all comes out? not even cold water?

Sounds like a possible air lock to me

If so a good trick is to pop your thumb over the outlet of the kitchen tap and turn both handles on

 

[wilkinson_rober]

When we turn on any hot water tap/shower in the house we get a couple of drips and then nothing for about half an hour. Slowly the dripping comes back and then increases, and after 40 minutes or so the water starts to come through fully. We then get full hot water and normal pressure. Its slowly got worse though. Two weeks ago we were having to wait 30 seconds for hot water, and its gradually getting longer and longer.

When a cold tap is turned on it comes out at normal pressure. So, e.g. when you turn the shower to cold its full pressure, and when you turn the knob round towards hot the pressure drops and drops until nothing comes out. If you leave it like that for 30 mins or so you will eventually get hot water coming out at normal pressure.

Many thanks for your answer, I'll give it a go!

 

[ripsoco]

Hi, did this work?