Header tank not draining??

[matt5791]

Drained most of my central heating system to repair a leak on a radiator and insert a new and additional drain valve (more convenient location).

The system is a normal vented system.

Turned on the water to refill, header starts to fill and I realise the new tap is not properly closed. So turn off the water again, properly close drain tap, and turn on water to refill system.......

But I cant hear the header filling as expected, and check to find it is full and the water seems to not want to run into the system?? I have the drain taps open and rad. vents open, but the water in the header tank just sits there!!

Help!

Thanks for any ideas or advise,
Matt

 

[seco services]

you have a blockage in the feed pipe to the system
usually where the feed tee's into the system pipework.

 

[LUNAT]

HI

looks like there is AIRLOCK in the pipework

 

[JohnD]

You have a blockage in the feed pipe.

what you have described is very typical

It is most likely in the Tee where teh feed pipe joins onto the main pipes. This is probably close to the pump.

You might be able to blow the blockage out with a hose on the Vent pipe (curved over the top of the F&E tank) otherwise you will have to cut out the Tee.

Once the water is moving you will need to use a chemical cleaner like Sentinel X400 to break up the hardened sediment (otherwise it may cause another blockage, and it may damage your pump or colect in the boiler)

edited: too slow!
//www.diynot.com/search/forum....t=3&author=&search=Search+Forum&mode=advanced

edited again:

If you have plenty of money you can pay someone to powerflush it. If you have only £100 you could fit a Magnaclean yourself as well as using the chemical.

 

[JohnD]

this might dislodge the blockage (not my picture)
see //www.diynot.com/forums/viewtopic.php?p=749583#749583

take the fish out first

 

[matt5791]

Thanks very much for the helpful replies - I loosed the joint where the feed pipe joins into the main system (yes, near the pump) and the was a pause, followed by gurgling and then the water started to rush out - once reconnected it seems to be fine now.

I'll consider the clean out.

Many thanks,
Matt

 

[JohnD]

I'll consider the clean out.

considering won't stop it blocking again. You will not know it is blocked until it gets so short of water that it goes wrong.

removing sludge will improve efficiency and reduce wear

 

[matt5791]

Thanks for that - Ill look out for Sentinel X400 and the Magnaclean.

Does the chemical simply get poured into the header tank?

Matt

 

[JohnD]

you drain a couple of buckets of water out first with the ball float tied up, then add the chemical and stir it in so it is drawn down into the system during refill.

bale out any mud from the F&E first and sponge it clean to avoid adding more sediment.

you will know it is working when the rad water goes inky black

X400 is a very mild non-acidic cleaner, it just loosens sediment.

you ought to drain the whole lot out within a month and rinse clean as some of the loosened dirt will be non-magnetic. however the Magnaclean will continue working indefinitely and is easy to empty.

The cleaning chemical will cost £15 and when you have finished, add X100 Inhibitor to prevent further corrosion. That will treat 100 litres of water which is enough for most houses.