Airlock? No hot water from pump in gravity fed system.

29 Dec 2019
Reaction score
United Kingdom

I am not getting any hot water from my hot water taps/two showers which are fed from a water pump.

  • It's a gravity fed system
  • Hot water still coming from sources not linked to the pump (kitchen, bath, bathroom sink)
  • No hot water in two showers or en-suite in attic room (hot water tap runs dry)
  • All taps have ball mixers, meaning hot and cold can't be on at the same time
I have tried blocking the tap with the hot tap on to try and build pressure as well as connecting a hose pipe to the cold water feed in the attic shower and the hot water tap in the attic sink and had them both on for some time however no hot water is coming out of the shower/attic sink taps, still.

I've also tried draining the whole system, bleeding all the radiators and then filling the system back up.

At my wits end on how to fix this. Does anyone have any further suggestions?

Thanks in advance.
Sponsored Links
Erm a bit pointless draining the system if that was the the radiator systems you drained, filled and bled as that has nothing to do with thew hot water (HW) that comes out of the taps apart from the water in the CH system heats up the cold as it runs through the hot water cylinder coil.

The system you need to look at is the cold cistern in the loft > the hot water cylinder> from the cylinder to the pump > out on to the hot water outlets that are connected to the pump.

You need to work your way back, if you don't get any water out of the hot outlets then you need to go back to your pump and see if you have a feed to the pump. Isolate the hw cylinder (there will be a gate valve on the supply pipe to the bottom of the cylinder) and then take the feed pipe to the pump off, open the valve slightly and see if you get flows from the feed pipe, if it does then work you way forward and test at each point.
Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local