Underfloor heating - Cylinder unexpected expansion

[MURRAY]

Hello. Last month I had a plumber install my underfloor heating system but it failed when he tried it (the base of the hot water cylinder popped out). He has not returned and I wander if anyone could explain where the problem might stem from. Basically I have a copper hot water cylinder, heating water via immersion (free electric due to wind turbine, with automatic shut off when not operating). Water goes from here to A Myson UFH thermomixing valve to circulating pump (Grundfos25 60 130 setting 3) to manifold and into heating loops (120m total length) then returns to manifold and back to mixing valve. The cool water goes towards a circulating pump (Grundfos 15 50 130 setting 1) before returning to the cylinder. A pressure vessel is located above the cylinder. The system was filled with cold water initially with the tap then closed to create a closed system. Is there an obvious flaw in the plumbing here? Is there a need for the return circulating pump between the mixing valve and the cylinder. After the cylinder popped the plumber indicated that a small water tank above the cylinder may be more appropriate than the pressure vessel!! Any help much appreciated

 

[SimonG]

That'l be the standard hot water cylinder you are using then? for a vented hot water system. Now you've pressurised it it's deformed. You've been lucky.

Who's idea was this design?

 

[snowhead]

Ah,, the old too much water in too small a space problem.

Not helped by unsuitable storage vessel, inadequate expansion capacity, lack of any mechanical safety devices, lack of any electrical safety devices and lack of advice from the "Plumber"

 

[Ray Stafford]

Hi Murray, and welcome to the forum.

Could you post a diagram of the design? What I think you are describing sounds so horrible that I can't believe anyone has done it.

 

[Barry98]

Certainly not a competent person , can't oh claim of there insurance ?

 

[mfgs]

Post a picture or draw a diagram, I am struggling to work out exactly what has been done. It doesn't sound great though.

 

[Rickster123]

A picture speaks a thousand words Murray!

 

[supper plumb]

i didnt do it before any ones say i did lol was there any ptfe used if ot theres your problem

 

[Howsie]

Sounds like an UFH circuit has been added to an open vented system which has been sealed. Can't see an issue with this unless its been plumbed incorrectly.

 

[Dotty]

Sounds like an UFH circuit has been added to an open vented system which has been sealed. Can't see an issue with this unless its been plumbed incorrectly.

Unless the vented cylinder has been plumbed as unvented.

Could be popcorn time!

 

[SimonG]

That's how I read it 🙂

 

[Howsie]

Where did you find this plumber? If he's converted it to an unvented system then you're going to get very very wet very soon and your insurance company will run a mile.

 

[Howsie]

Where did you find this plumber? If he's converted it to an unvented system then you're going to get very very wet very soon and your insurance company will run a mile.

 

[supper plumb]

sounds like to mut pressure if the tanks has poped

 

[Ryan LPS]

Ticking time bomb for it to blow if I was you I'd get a picture up for us to see what this plumber (if you can call him that) and then if its what It sounds like call a plumber out to make it safe

 

[Dannyparty92]

This sounds.... Interesting.

 

[chris watkins]

Trying to get to the bottom of this, who thought that a wind turbine would provide enough energy to run a 120 Metre underfloor heating system with a copper cylinder as a buffer?? are we talking large scale ???

 

[Koogatubac]

Tick tock tick tock tick tock....

Murrey sounds like he knows a bit... Maybe hes plumbed the system in? And created a bomb

 

[lame plumber]

surely the uflr system should be running through a coil in the cyl and not as part of the hw sys, so the cyl deforming is a symptom of a much bigger problem, failed coil, misconnections etc. Back to square ine time imho

 

[Ryan LPS]

Murray can you get a picture up please as I specialise in renewble and biomass and reli wanna see the mess this plumber has done. And of cause see if I can see a solution.

 

[julesverne]

maybe he's gone to sort out the original plumber with a few swift blows to his chops

 

[Toxic Ted]

perhaps Murray is still orbiting the earth .......

 

[supper plumb]

tick tick BOOM it was a terrorist attack

 

[Ryan LPS]

Perhaps the cyclinder has gone boom.

 

[Ryan LPS]

He still could run the system but need significant changes.