Wet ufh. Not all rooms warming.

[JDAB]

Hi, hoping for a little advice.

 

After switching on my ufh I’ve discovered that two rooms in our bungalow aren’t warming. The system was installed before we moved here (just over 10 years ago) but we haven't altered anything in that time.

 

Upon closer inspection I found that the two actuators, linked to the thermostats in those rooms had stayed closed. I removed them, tested the pins (which all tested similarly to the others, firm but they do move) and re-attached. Voila! (I thought) as they slowly rose up. However, after several hours, no heat came to the rooms…

 

I’ve tried testing each non-working thermostat in isolation by turning them to max but no joy. I can’t feel heat coming from the supply pipes leading to those rooms either but the actuator tops do get warm. I’m wondering, is if this all sounds familiar to anyone? And is it something can resolve myself? Or am I in, call out a professional territory?

 

We did have a new boiler fitted around March this year. Though we haven’t had any problems with it.

 

We also had a small leak coming from the return area of the manifold. This was repaired shortly after boiler was fitted by the same person. I have no idea how long we had the leak but when I did find it, it was a single drip every 30 seconds or so.

 

Attached photos of the set up. And one (where i'm pointing) from when I noticed the leak.

 

From left to right on the manifold, the seven connected rooms are performing as follows:

 

O - NW - W - W - NW  - NW - W

 

(O = Off, W = Working, NW = Not working)

 

I do have Bosch AdvancedTemp Infrared Thermometer. Incase it help with fault finding.

Thank you for any help in advance.

[JohnMo]

Take the actuators off on the not working loops, does the flow meter move down (the red lines). Removing actuator opens loop, regardless of call for heat.  If this resolves issue you have an issue with electrics.  If nothing changes you have an issue with air in the system, get the plumber back to bleed the loops.

 

Takes all the junk off the UFH loop pipes. Look to box in, so they don't get damaged.

[Gus Potter]

32 minutes ago, JohnMo said:

If nothing changes you have an issue with air in the system,

Agree a bit of air can cause havoc. 

 

One way to purge this is to shut off the other loops and open the air vent. You'll need a bucket and a few towels to catch the water. 

 

Give it a good go and don't forget to top up the inhibitor once you have finished. 

[JDAB]

Hi, thanks for the replies. Really appreciated. Sorry for the late response, my daughter isn't well so I've been preocupied.

 

JohnMo, I've taken off the actuators and the red markers don't move. Should they start moving soon after removing, or should I leave them for a few hours to be sure?

One thing I have noticed is that, although the pins move, the part that surrounds them (sorry I don't know what that's called) is much lower down than the working ones. Photos attached.

Gus, I'm trying to find a manual on the system but finding that difficult. I haven't had to purge the sytem before so not sure what I'm doing.

The plumber that fixed the system is no longer available unfortunately. Trying to save myself a little money and fix myself if it's straight forward enough. Watching videos online it seems pretty easy other than re-pressurising.

Thanks again.

Edited 9 hours ago by JDAB

[vala]

If you need a guide for purging air out of the loops, we have done it using the method describe in this manual from Wunda.

Noticed a fair bit of air coming out even from loops we thought had been fully purged.

May be worth a try.

https://www.wundagroup.com/wp-content/uploads/2019/10/M07-generic-Wunda-premium-Manifold-25-4-2018.pdf

[JohnMo]

38 minutes ago, JDAB said:

JohnMo, I've taken off the actuators and the red markers don't move. Should they start moving soon after removing, or should I leave them for a few hours to be sure?

The red marker move down to. indicating flow had started. They move in response to water flow. 

 

The brass thread section with the pin at the centre sets your flow rate. Would assume screwing upwards increases flow. So it may be worth screwing outward (take note of how far you move in number of turns) watch the red marker if that starts to move that may be your issue.

 

If the red marker hasn't moved after a few of turns that isn't the issue. You are most likely looking at air in the loops.

 

To get things moving. Go round each room and turn off the thermostats (or set to lowest setting), once all are off the pump will stop. Now go to one problem room and set the thermostat on. Pump should start. Open bleed on manifold top rail (white radiator bleed thing - top left). It may spray water so slowly open have a towel handy. You may have to open and close a few times. Once the loop starts running, leave for 5 mins. Close the demand at thermostat. Repeat for each problem loop. Report back.

[JDAB]

Will report back. Just to quickly add. The pins that were moving (i'm sure of it) are now solid. I noticed because I was finding it very difficult to put the actuators back on.

[JohnMo]

35 minutes ago, JDAB said:

Will report back. Just to quickly add. The pins that were moving (i'm sure of it) are now solid. I noticed because I was finding it very difficult to put the actuators back on.

I would unscrew the brass bit and see if that frees things up the brass bit may be so far down they have fully closed off flow and pin has nowhere to go?