Underfloor heating on in certain zones when hot water is on

[Manishpatel1971]

Hi, I am new to this site and I hope I am posting my query in the correct forum.

i have a problem with my underfloor heating, I will try and explain as best as I can.

i have underfloor heating in 2 floors, ground and 1st. Each floor has multiple zones effectively each room in the house.

i have noticed that during th e summer when we have the heating turned off, a few zones on the ground floor are becoming hot when the hot water is on?

i checked the manifold and found the pipes in the zones are indeed hot when the hot water is on and cool when the hot water is off.

any help or advice would be appreciated.

 

[snowhead]

Zone thermostats set too high or faulty

Or actuators on the manifold faulty for each of the affected zones.

 

[Manishpatel1971]

Zone thermostats set too high or faulty

Or actuators on the manifold faulty for each of the affected zones.

Thanks for responding snow head.

the heating is actually turned off, the room stats are set to 5c and when I look at the actuators they are all in the down position.

it is very weird almost like it is plumbed incorrectly???. I sincerely hope that is not the case.

 

[stevetheplumber]

if the actuators are shut then you shouldnt get circulation i would swop the ones that are getting hot with ones that have stayed cold to rule out actuators

 

[Dickie]

You may have heat migration as a result of the system being piped incorrectly. If the HW Return is not the first tee on the Common Return pipe, then you've a problem.
HTH

 

[Ermintrude]

When hot water is on is there any power to ufh pump? If not actuators not closed properly and heat migrating! U could install 2 port zone valve on flow to ufh manifold and a balancing valve on return and this would fix migration problem.

 

[Dickie]

When hot water is on is there any power to ufh pump? If not actuators not closed properly and heat migrating! U could install 2 port zone valve on flow to ufh manifold and a balancing valve on return and this would fix migration problem.

If its a incorrectly piped Common Return, then a simple NRV would be the answer.

 

[Gray0689]

Thanks for responding snow head.

the heating is actually turned off, the room stats are set to 5c and when I look at the actuators they are all in the down position.

it is very weird almost like it is plumbed incorrectly???. I sincerely hope that is not the case.

Sounds more like a wiring problem as if heating off pumps for manifold and all actuators closed then as said there is no circulation
As for heat migration you need a hell of a lot to heat underfloor without circulation

 

[Ermintrude]

Possibly if boiler has a wiring fault I.e perm live to s/l pump running and if no bypass or very high bypass system flowing through ufh? Not migration but a vacation for the water? Couldn't recall from op (original post?) that the ufh pump was off?

 

[Dickie]

You have a valid point Gray dear boy. However, some system pipe work are a complete disaster!! What you must remember; UFH is sometimes done by your generic 'Builder'. And I've seen some corkers!!

 

[kay-jay]

Rather than all this speculating about wiring faults would it not be more prudent to ask the op if the system used to work correctly and if the fault is a new occurrence??

 

[Gray0689]

Rather than all this speculating about wiring faults would it not be more prudent to ask the op if the system used to work correctly and if the fault is a new occurrence??

Correct mate
And a few pics may help to

 

[AWheating]

Rather than all this speculating about wiring faults would it not be more prudent to ask the op if the system used to work correctly and if the fault is a new occurrence??

no, i think its the fuloo valve or the yellow wire