Pressure testing underfloor heating

[Rileyfinn]

Hey is it usual to pressure test underfloor heating with water via a testing pump?

 

[Norcon]

Yes.

You could test it to high pressure with air and if punctured during the screed laying will give an enormous swooooosh and maybe snake and whip lash round the room leaving the navvies in a state of shock and will be certain to be seen.

 

[Richardthe3rd]

Hey is it usual to pressure test underfloor heating with water via a testing pump?

You'd do a hydraulic pressure test on all loops & manifold. A gauge is attached at the manifold, it's left on test prior & throughout the screeding or before a wood floor is fixed down. Remember to tell the hairyarsed builders not to damage the pipes & to monitor the gauge throughout the pour.
HTH

 

[Rileyfinn]

can you test with water via a water pressure tester?

 

[Richardthe3rd]

can you test with water via a water pressure tester?

I'd purge all loops with mains water pressure, via hose or whatever. A lot of places here in Scotland we can get 6Bar mains water pressure. Then attach a pressure test box & test it to 9-12bar, that should be enough. Just ensure everyone knows to keep an eye on the manifold gauge..........

 

[Fallout]

if just pressure testing via a standard water pump pressure testing gauge is there any need to purge air as this would mean more pumping?

 

[Fallout]

Can it just be filled off the mains through the fill point and use the pressure gauge on manifold to read the pressure would save a lot of pumping.

 

[Fallout]

is it important to get all the air out if pressure testing or can this be done when filling the system properly not just the manifold.

 

[Richardthe3rd]

Can it just be filled off the mains through the fill point and use the pressure gauge on manifold to read the pressure would save a lot of pumping.

Is there an echo in here??

Manis water pressure may not be enough mate. Though 3 times the working pressure is the normal recommendation. I like to have a very high pressure, then if some rsole nicks a pipe, it'll hopefully show up quickly.

 

[Fallout]

do u have to purge the air when pressure testing as this would mean alot more pumping any air could be bleed when properly fillin the system??

 

[Agile]

For the test to me meaningful all the air needs to be expelled.

This is because the oxygen will dissolve in the water and give the appearance of a leak.

Then over a longer period the nitrogen will dissolve a little giving further appearance of a leak.

However because the plastic tube is slightly elastic it expands a little at high pressures too.

So to make everything as useful as possible its necessary to get all the ait out.

Tony

 

[Richardthe3rd]

do u have to purge the air when pressure testing as this would mean alot more pumping any air could be bleed when properly fillin the system??

Further to Tony's insightful input, get the air out as soon as possible.

 

[Fallout]

I've never removed air when pressure testing cold and cold pipework and never had a problem. Is this not the same?

 

[Fallout]

For the test to me meaningful all the air needs to be expelled.

This is because the oxygen will dissolve in the water and give the appearance of a leak.

Then over a longer period the nitrogen will dissolve a little giving further appearance of a leak.

However because the plastic tube is slightly elastic it expands a little at high pressures too.

So to make everything as useful as possible its necessary to get all the ait out.Tony

Would opening the automatic air vents on the manifold expel enough air to pressure test?

 

[Richardthe3rd]

For the test to me meaningful all the air needs to be expelled.

This is because the oxygen will dissolve in the water and give the appearance of a leak.

Then over a longer period the nitrogen will dissolve a little giving further appearance of a leak.

However because the plastic tube is slightly elastic it expands a little at high pressures too.

So to make everything as useful as possible its necessary to get all the ait out.Tony

Would opening the automatic air vents on the manifold expel enough air to pressure test?

You need to purge each loop at a time. Connect a drain hose to the return manifold drain, connect a mains water hose to the manifold flow drain valve, shut off all loops - both valves. Open the drain c.ck on the return & the first return loop valve, then open the first loop flow valve, so you're flushing through the first loop: flow-return-drain.

Then shut that loop & flush the second etc etc.