i need to replace an old metal central heating header tank

[ntvrman]

i need to replace an old metal central heating header tank, with a plastic one, dont want to turn off heating. should i just make sure there water in the down/feed pipe. then remove it then just top it up again once in place.

Or is there anything else i need to do first.

Neal.

 

[RigidRaider]

Others more expert than me will be along soon but I would use it as an opportunity to give the whole system a clean out, especially since I would be fitting a clean new header tank. I would drain the lot, replace the tank then refill with fresh adding Fernox or similar. While the system was drained down I'd take the opportunity to deal with any weeping valves, rusty radiators or anything else that looked dodgy.

The only problem with this is that you might end up creating a complete headache for yourself as more problems came to light. Whatever you do, don't start it on a Saturday afternoon because plumbers' merchants will be closed and you'll be forced to buy bits at B&Q or Soditall prices and you won't get the free advice that a proper shop would give you.

But yes, if time was short you could just drain enough to dry the tank then simply replace it and refill.

 

[londonboy]

I am not a plumber however I know some systems (wood burning etc) must have a metal tank due to the risk of boiling water in the tank.

 

[StevenJames125]

if the heating is on, then the water will expand a little from the cold feed pipe into the header tank (due to expansion) - if you removing the tank with the heating on you'll get a bit of trouble.

Best to really give system a flush and fill up from fresh with new inhibitor

 

[twgas]

What is wrong with turning the heating off, not exactly freezing at mo.