Under Floor Heating with my GSHP

frslam

Hi all, Happy New Year. 
I have a problem with my underfloor heating, unfortunately I suspect it could be a messy fix. When it was installed in 2009/10, one of the plumbers kink'd the pipe to one of my upstairs bathrooms. The pipe runs in spreader plates fixed between joists with insulation fixed below. Instead of cutting out the kink and patching the pipe, the plumber tried to straighten it out then used pipe clips to fix the pipe to the underside of the floor. The part of pipe that was kink'd was on a bend, not in a spreader plate. The floor heat to that bathroom was OK for a while, now it's the only cold floor in my house. 
I've ordered new return pins and flow meter heads for the manifold - to test the easy stuff first, the return pin was stuck down but I managed to open it with pliers, floor still cold. I have standard lockshield flow caps on the manifold but thought I'd replace them with metered flow caps, so have them on order. Also going to replace the return pin cap. 
Is there anything else I could do before the drastic stuff, like opening the ceiling below the affected bathroom to check if the pipe is OK or whether it's kinked up again?
Was thinking of attaching pipes to the flow/return vents, shutting off all but the affected heating loop and see if I can get a flow through the circuit? Very slight possibility that the affected circuit could have a large air lock? Suppose a loop flush wouldn't hurt and pretty easy to do. Would I need to bother shutting off all other flow & returns or just the flows to the other circuits? Many Thanks for any advice!

Netexporter

Could you add a heated towel rail to make up the heat deficit?

frslam

Netexporter said:

Could you add a heated towel rail to make up the heat deficit?

Already done that. When the house was built, I ran twin and earths from a specific wall in each bathroom to a central point in the house for future expansion. Bathrooms in my house have electric heated towel radiators, all controlled by centralised timers from my under stair cupboard. The bathroom floors are travertine type tiles so the bathroom with the dodgy loop is uncomfortably cold, even when wearing socks, never mind in bare feet. I guess the easiest solution to attempt to find the problem, would be to flush out that particular circuit and see if it runs through, if it is air pockets hopefully mains water pressure onto the manifold flow (vent) would push it through. Thought I'd post on here to se if there are any other ideas. Once my new return pins and flow meter heads arrive I'll be able to check if there is any debris in the ports at the manifold.

matelodave

 My manifold does have flow meters on each loop so I can see if there's a problem but failing that you you'll have to try and isolate the floor loop to try and check whether its blocked or has an air lock. I guess you'll have to do that anyway if you are going to change the control pin and fit flow meters.

I dont know how much control you've got but my manifolds have a valve on the flow and return to the heating unit together with flow control pins (previously with actuators on them, which I've take off) and flow meters.

You might find this helpful - 
https://www.bing.com/videos/riverview/relatedvideo?q=underfloor+heating+flow+meters&mid=8B86E60EDBD78D843A2D8B86E60EDBD78D843A2D&FORM=VIRE

sony56

I've a similar issu since few months, but since it's only in a part of my house where I don't go that much, I didn't tried to fix it. But thanks for that discussion, I've read the comments and advice, think I'm gonna try all of that !
And I hope you'll fix your issue soon

frslam

matelodave said:

 My manifold does have flow meters on each loop so I can see if there's a problem but failing that you you'll have to try and isolate the floor loop to try and check whether its blocked or has an air lock. I guess you'll have to do that anyway if you are going to change the control pin and fit flow meters.

I dont know how much control you've got but my manifolds have a valve on the flow and return to the heating unit together with flow control pins (previously with actuators on them, which I've take off) and flow meters.

You might find this helpful - 
https://www.bing.com/videos/riverview/relatedvideo?q=underfloor+heating+flow+meters&mid=8B86E60EDBD78D843A2D8B86E60EDBD78D843A2D&FORM=VIRE

Thank you. I have Emmeti (Mk 1 - Nickel/Brass) Manifolds. There is a bleed port on flow and return rails that'll fit a washing machine hose or garden hose-lock type fitting. Only a case of shutting the flows to 6 out of 7 ports, attach a hose and open the valves to release pressure (after isolating the manifold at the flow/return pipes) then attach the hose from a mains water tap to the flow and a hose from the return to a bucket and see if I get at least a certain amount of flow through the circuit.

frslam

sony56 said:

I've a similar issu since few months, but since it's only in a part of my house where I don't go that much, I didn't tried to fix it. But thanks for that discussion, I've read the comments and advice, think I'm gonna try all of that !
And I hope you'll fix your issue soon

Thanks. I have Emmeti (Mk 1 - Nickel/Brass) Manifolds. There is a bleed port on flow and return rails that'll fit a washing machine hose or garden hose-lock type fitting. Only a case of shutting the flows to 6 out of 7 ports, attach a hose and open the valves to release pressure (after isolating the manifold at the flow/return pipes) then attach the hose from a mains water tap to the flow and a hose from the manifold return vent to a bucket and see if I get at least a certain amount of flow through the circuit. I can only hope that it's not the kink in the hose. Not sure what the plumber was thinking - if you kink a hose at all during installation, you should always cut out that part of the pipe and patch it. Using pipe clips, in my opinion, to try to stop the hose from folding where the kink occurred is not a good long term solution. Pipe clips only have 10-15. tack type nails to hold back pipe which could be filled to a couple of BAR pressure

frslam

sony56 said:

I've a similar issu since few months, but since it's only in a part of my house where I don't go that much, I didn't tried to fix it. But thanks for that discussion, I've read the comments and advice, think I'm gonna try all of that !
And I hope you'll fix your issue soon

I believe I've just fixed my dodgy loop. Took the return head off the circuit and using a pair of pliers, I plunged it a few times like you would plunge a drain. Now that circuit is getting the floor above 24c just like the other rooms on the first floor. I'm in the Highlands (Isle of Skye) and live by the coast. Temperature outside is in the minus just now but a 24.5c floor is enough to keep the rooms at between 20-21c air temp. Thank You all for your comments