Any plumbers in here

[dannyjpuk]

Hi all just a question since I moved into my place 10months ago the hot water coming from the tap doesn't seem right it starts fine presure wise but eventually the water starts and caughts and splutters out like there's a air lock then the presure drops to a Small little trickle some times I just have enough to get a decent bath I'm guessing it's a pump that's on it's way out ???? I ran all the taps and flushed the toilet before.... my cold is fine presure wise it's just the hot that eventually stops

[Ben50n]

It depends what type of hot water system you have?

You may have a combi boiler with no holding tank, the domestic water is heated instantly like a geezer. Loss of water flow, would normally be reduced mains pressure.

or, you may have a hot storage tank, loss of flow could be caused by a slow refilling maybe a sticking ball valve?

Unless you live in a high up flat, the pumps are normally for pumping the hot water around your radiators.

[scotty84]

What boiler system you got buddy?

If you have an immersion heater (copper tank) its possable that its not filling properley....You will have a header tank in the loft that feeds the copper tank, this sometimes gets full of crap (limescale etc) and can cause a blockage and only allow water to trickle through....Or the ball valve may need changing as its shot and only trickling water in.
Sorted one the other week same problems turned out to be the ball valve..

Hope it helps buddy......But if its a combi boiler (no copper tank) get a heating engineer in matey as its a little more complicated lol.

[dannyjpuk]

What boiler system you got buddy?

If you have an immersion heater (copper tank) its possable that its not filling properley....You will have a header tank in the loft that feeds the copper tank, this sometimes gets full of crap (limescale etc) and can cause a blockage and only allow water to trickle through....Or the ball valve may need changing as its shot and only trickling water in.
Sorted one the other week same problems turned out to be the ball valve..

Hope it helps buddy......But if its a combi boiler (no copper tank) get a heating engineer in matey as its a little more complicated lol.

It's a older house so I have a back boiler the central heating and the hot water is fine ....... Yes I have a tank in the loft so shall I climb up and have alook at the ball Thingy lol

[scotty84]

It's a older house so I have a back boiler the central heating and the hot water is fine ....... Yes I have a tank in the loft so shall I climb up and have alook at the ball Thingy lol

Yep you need to get up in the loft and have a look at your ball valve buddy. My betting is its shot and only trickling water in

[headscratcher]

check the ball aswell,
the arm can corrode and this can be adjusted to allow the water to fill the tank quicker,
be careful with it tho,
get someone /or run a bath to full,
empty and keep an eye on the tank,

[big jon]

i changed the round tank in the loft for the coffin type with the header tank we also have the copper cylinder to hold the hot water the glass fronted fire heats the water but when we tried the hot water it just spluttered so i thought it was an air lock so i put the hose on the mains feed and blew the air out, result, i thought but no, over night it seems to air lock again so in the morning i have to turn the downstairs hot tap on until it splurts and gurgles and gets rid of the air, funny thing is its ok during the day when it gets used regularly, so it looks like the plumber is going to get a call out

[rich r]

Another possibility - particularly with solid fuel boilers as you can't turn off the heat easily - is that the water is getting too hot and forming bubbles in the pipes. The usual way of preventing this is to have a thermostat that turns on the radiator pump if the hot water temperature exceeds 80°C. Similarly you should have a thermostat in the radiator pump supply that turns it off if the hot water temperature drops below 40°C.

We have a big coal/wood boiler that supplies all our hot water (no gas or oil at my house), and had to fit these two temperature switches when it was installed. Not all installers bother, as usually plumbers do the pipework and boiler specialists do the boiler. But really it's the plumbers who need to read the installation guidelines for the boiler to see what it needs.

You can test this by turning the boiler's air flap setting right down at night, that shouldn't allow the water to get too hot.

[dannyjpuk]

That's great chaps I'll have alook and do what you have said when I'm off

[beat275]

sounds to me like an air lock