Fixing Expansion tank back on wall

[craig1912]

Some clown thought a couple of rawl plugs through plaster board was enough to fix expansion tank to the wall. Woken last night as it fell off!

What are the best fixing to secure it properly. It s an external wall and there is a small gap behind the plasterboard and then the thermal grey blocks.

Would bigger rawl plugs into the thermal block be OK?

[craigthecoupe]

Is the plasterboard on studwork, or dot and dab? Probably better trying to get something solid. Whats the gap like behind the board? If its too large I imagine the fixings will sag in time?

[wolfracesonic]

Rigifix or similar.

[JoshSm]

Depending on the weight maybe fix it to a board and then fix the board to the wall, four fixings over a wider area is always going to be better than two close together.

[Mr Pointy]

Corefix - the red boxes, not the blue & green. They bridge the gap into the blockwork.

https://www.amazon.co.uk/s?k=corefix&crid=1A82...
https://www.screwfix.com/c/screws-nails-fixings/wa...

[craig1912]

Mr Pointy said:

Corefix - the red boxes, not the blue & green. They bridge the gap into the blockwork.

https://www.amazon.co.uk/s?k=corefix&crid=1A82...
https://www.screwfix.com/c/screws-nails-fixings/wa...

Thanks- was just looking at these after watching a you tube video

https://www.screwfix.com/p/corefix-connect-heavy-d...

[craig1912]

craigthecoupe said:

Is the plasterboard on studwork, or dot and dab? Probably better trying to get something solid. Whats the gap like behind the board? If its too large I imagine the fixings will sag in time?

It’s dot and dab- gap is only 5-10 mm so Corefix look ideal

[wolfracesonic]

Corefix, very similar to Rigifix I believe

[craig1912]

wolfracesonic said:

Corefix, very similar to Rigifix I believe

👍

[Magic919]

Would be worth checking it hasn’t failed.

[craig1912]

Magic919 said:

Would be worth checking it hasn t failed.

Didn’t fall far but how would I check it hasn’t failed?

[Magic919]

They don’t fail because of falling. They double in weight when they fail and fall off the wall.

Does it still have air and pressure or is it full of water?

[craig1912]

Magic919 said:

They don t fail because of falling. They double in weight when they fail and fall off the wall.

Does it still have air and pressure or is it full of water?

Feels quite heavy and there is water in there but not full of water. Pressure dial is normal. I don’t know much about this stuff so probably get a plumber out to check.
Hot water seems normal.

[Mike Legerwood]

I prefer DryLine Pro to the corefix version.

https://www.drylinepro.com/

[Mr Pointy]

Mike Legerwood said:

I prefer DryLine Pro to the corefix version.

https://www.drylinepro.com/

Why, what makes them better?

[craig1912]

I’ve ordered the Corefix ones now

[ducatikim]

craig1912 said:

Feels quite heavy and there is water in there but not full of water. Pressure dial is normal. I don t know much about this stuff so probably get a plumber out to check.
Hot water seems normal.

Assuming that the heating system is cold and the hot water tank isn't calling, there should be no, or next to no water in the expansion vessel.
The precharge should be set to the same pressure as the cold fill pressure in the system. Isolate, drain down and re-charge the vessel via the schrader valve on top.
As previously mentioned, not unknown for the rubber membrane or bag to fail, in which case replace as required.

Eta Why don't so called heating engineers ever carry out the simple check on precharge when they're doing a boiler service?

Edited by ducatikim on Sunday 12th July 14:31

[craig1912]

Probably going to get someone in to check over once I ve remounted on the wall.
How do I get access to the Schrader valve?

[Magic919]

Try the other end.

[spitfire-ian]

ducatikim said:

Eta Why don't so called heating engineers ever carry out the simple check on precharge when they're doing a boiler service?

Ours plumber checks ours when doing a boiler service. He's quite pricey compared to others though but does do a very thorough job with anything we've asked him to do. He does also have a tendency to go off abroad skiing/surfing/lounging around when he feels like it