Advice needed. Issues with underfloor heating and hot water system for new build

[Ermintrude]

Did he try blowing out the coil with mains

Surely that will blow the mains fuse? 100a through coil?????? Oh water right !

Close all your valves to zones and boiler so only route from loop to drain off is the coil , open filling loop and drain off , open and close drain off to allow pressure to build and remove any bits?? No sawdust or plaster board ore even air in coil??

 

[Carrera]

Did he try blowing out the coil with mains

yes that was done today

 

[mark_mc]

have to agree with gray on this
everything is undersized
if all the circuits go back to the plant room you may be able to solve with a low loss header and pump to each manifold with separate pump
hot water return may be impossible without taking up floors
but would really look at pumping each manifold if possible, and it looks like 22mm doing the manifold in pic which i would be bring 28mm too, better looking at it than looking for it.

 

[Nostrum]

It looks like it could be reverse circulation does the flow/return that lead to the basement have a balancing valve on?

From the picture ( which is very hard to make out on an ipad) flow could be being forced down to the basement circuit then back through the coil and into the flow again which is then leading up to the UFH circuit which would add up with what your saying. A bit like a 1 pipe system.

How I haven't quite figured out yet, are you sure that valve is opening fully?

 

[Nostrum]

Is some of that Pipework 35mm?

 

[Carrera]

It looks like it could be reverse circulation does the flow/return that lead to the basement have a balancing valve on?

From the picture ( which is very hard to make out on an ipad) flow could be being forced down to the basement circuit then back through the coil and into the flow again which is then leading up to the UFH circuit which would add up with what your saying. A bit like a 1 pipe system.

How I haven't quite figured out yet, are you sure that valve is opening fully?

valve is definitely opening up properly
some pope work in the basement is greater that 28mm

 

[Gray0689]

valve is definitely opening up properly
some pope work in the basement is greater that 28mm

The flow return from boiler is 28mm

 

[Nostrum]

Yeah if you look at the right hand side 'manifold' 2 are 28mm up to the UFH and the one on the far right is 22mm, there is a reducer before hey tee so it must be 35mm, it then reduces on the tee under the boiler, so flow out of boiler is 28mm into a 35mm tee. That why the pump doesn't have standard valves.

If you isolate the basement manifold does your cylinder stop reverse circulating?

 

[stevetheplumber]

all looks well undersized to me

 

[Carrera]

Yeah if you look at the right hand side 'manifold' 2 are 28mm up to the UFH and the one on the far right is 22mm, there is a reducer before hey tee so it must be 35mm, it then reduces on the tee under the boiler, so flow out of boiler is 28mm into a 35mm tee. That why the pump doesn't have standard valves.

If you isolate the basement manifold does your cylinder stop reverse circulating?

Will have to test tomorrow and get back to you