Underfloor heating issues

philbk

When my underfloor heating system was installed 7 years ago there was no retardant / inhibitor added to the system to prevent the flow meters on each zone turning from clear to black. Now I can not see if there is any flow in certain zones and I certainly have issues with certain zones not heating as they should. Does anyone have a similar experience and how was it sorted. I could screw off the flow meters and clean them but I think I would have to drain the system and I am not sure how to do that. I would appreciate any help / advice. Thanks

blast06

To check on whether there is a flow ..... are the pipes on your manifold labelled ? If so, then you could check if the ones in question warm up when the heating is turned on from fully cold. Even if not labelled, you could figure out which are which by just leaving 1 thermostat turned up and seeing which pipes on the manifold warm up and so on.

philbk

Thanks for the advice. By turning the heating off I was able to clean the flow meters one at a time. I lost a little water but now I can see the flow rates. To my surprise all zones had a flow rate of approx 2lt/min. Despite this our master bedroom is always cold. I presume short loops do not need as high a flow rate as long loops? From what I can remember the master bedroom had the longest loops so I increased the flow rate to it this afternoon. I hope this sorts the problem!

shane0007

philbk wrote: »

I presume short loops do not need as high a flow rate as long loops? From what I can remember the master bedroom had the longest loops so I increased the flow rate to it this afternoon. I hope this sorts the problem!

This is correct, however, make a note of all flow rate adjustments you make in case you need to revert back or adjust further. It generally will take a few hours to see a reaction to your adjustment so patience is key.

philbk

I have increased the flow rate to the master bedroom but it hasn't made any difference. I can see that warm water is flowing through the bedroom loops but the temp increase is hardly noticeable! This bedroom has never warmed up properly over the years and the ensuite floor is always stone cold. I fear something more fundamental is wrong. I withheld part of the payment to the underfloor company as they didn't label the loops properly and weren't sure which loops were which after the screed was poured - this is an example of how thorough they were! I would appreciate any advice I can get as to what I can do next?

shane0007

Turn off all but one thermostats/zones & see which actuator lifts. When the actuator lifts, see if the heat is going to the correct zone. If not, they might need to be swapped. Repeat until all are correct.