DIY Doctor

Main navigation

Hot water in F&E Tank

Postby frank mcnally » Tue Dec 02, 2008 6:52 pm

about 2 weeeks ago I drained my central heating system to fit a new readiator and a thermostat valve and new lockshield.

On re-filling the system there was an airlock, to overcome this I connected a hose from the cold tap in the bathroom to the feed pipe from the F&E tank. Afer this system filled ok, all radiators working.

About a week later I discovered hot water in the F&E Tank. The hot water is coming into the F&E Tank via an open vent pipe from the heating coil in the hot water cylinder. There is another ventpipe into the F&E tank from the pump, this apperas to be ok.

I have changed the boiler thermostat, the pump is running on minimum. It as if the water is being taken from the F&E tank via the feed pipe and circulating back up the vent pipe.

The system apperas to be working correctly except for this issue, I am now at a loss as to what to check next.
frank mcnally
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Sat Nov 22, 2008 5:49 pm


Simply Build It

Postby plumbbob » Wed Dec 03, 2008 10:21 pm

Topics already discussing this problem. ... hp?t=15274

The feed and expansion connections to a vented heating system should be on the same leg, and no more than 150mm apart to prevent this happening.

Your system may have started this because the pump speed is now set higher or you have shut the lockshield valves too far when balancing the radiators. Either way, the system has a built in design fault.
Rank: Project Manager
Posts: 1891
Joined: Wed May 07, 2008 9:59 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics