Underfloor heating troubleshooting
Fix UFH problems with our online troubleshooting
Underfloor heating not working and need technical support fast? Try our online guidance below. You can also view diagrams of your UFH manifold to select the relevant spare part, most of which can be bought from the Nu-Heat webstore.
If you’re still experiencing problems with a Nu-Heat underfloor heating system, please contact our Technical Support Team via tech.support@nu-heat.co.uk or call 01404 540745 between 8am and 5pm, Monday to Friday.
Troubleshooting common issues
Single flooring zone not heating up
- Sticky pin valve actuator
Spray with silicon and gently ease the pin up and down until free. Do not use WD40 or any hydrocarbon based lubricant. - Underfloor heating actuator failed
Check that the actuator head is proud after 3 minutes of calling for heat – if not, replace it. Alternatively, it may not be the actuator – it could be a wiring board or thermostat issue. - Faulty underfloor heating thermostat
Call an electrician – check for live and switched live return. If your system uses wireless, battery-powered thermostats then it’s also a good idea to check the batteries. - Thermostat not set up correctly – E1/E2 errors
neoStat – if you are using a neoStat please view page 9 of the User Guide which explains this error code.
neoAir – if you are using a neoAir please view page 10 of the User Guide which explains this error code. - Air bubble or airlock in UFH loop
If the underfloor heating is patchy, low flow you will notice the flow gauges trembling download our plumbing manual and follow the procedure for filling and flushing. - Flow gauges not been opened correctly
a) Lift the locking collar – do not remove completely
b) Turn the collar anti-clockwise to unscrew the isolation valve. Three turns will fully open the valve – do not exceed this. The isolation valve must be fully open before flow rate adjustment is possible
c) Push the locking collar back down to lock the isolation valve
d) Circuit flow rate can be adjusted by twisting the top of the gauge by hand to the desired setting between 0 and 4. Lift the white collar to lock the flow meter setting.
Multiple or all flooring zones not working
- Circulation pump failure
Check for air in the pump and check that the circulation pump is receiving a live signal from the Nu-Heat wiring board. - Pump relay on wiring boards
When a call for heat is present check that the relay makes a clicking sound and it switches. - Isolation valves closed on manifold
The isolation valve is open when it’s in-line with the pipework. If it’s at 90° angle to the pipe it is closed. - Blending valve pin valve stuck
Use silicon spray (not WD40 or any hydrocarbon based lubricant) and gently ease the pin up and down until it is free. - Air ingress
Download our plumbing manual and follow the procedure for filling and flushing. - Boiler not firing (no signal)
Check that the boiler is powered up and that the wiring board is receiving a live signal on (in) and sending this signal back on (out). - No power to wiring boards
Check switches and fused spurs.
Underfloor heating zone permanently on
- Faulty actuator (has it been energised/de-energised prior to fitting)
The pin valve may be stuck in the up position – use silicon spray and gently ease the pin valve up and down. - Faulty thermostat
Does the thermostat have a live supply and a switched live return when it is turned up?
UFH pump running all the time or won’t turn off
- Pump relay stuck on the wiring board
Replace the wiring board having checked the thermostat. - Faulty underfloor heating thermostat
Does the thermostat have a live supply and a switched live return when it is turned up? - Faulty underfloor heating actuator
There are no serviceable parts – replace the actuator.
Identifying your underfloor heating manifold for parts
Choose your manifold from the list below to help select spare parts.
If you need any further help, you can contact our Technical Support Team via techsupport@nu-heat.co.uk or 01404 540745 between 8am and 5pm, Monday to Friday.
Oct 1999 – Apr 2007 – Brass manifolds (OMDxx-C)
| No. | Code | Description | Buy online |
| 1 | OMD1E-C | Port extension kit | N/A |
| 2 | OMFG-C | Flow gauges | Buy online |
| 3 | G1560-C | Pump | N/A |
| 4 | TGD-C | Temperature gauge | Buy online |
| 5 | MPP1-A | Complete pump module | N/A |
| 6 | MPPK1-C | Pump module assembly | N/A |
| 7 | OMBV-C | Valve set | N/A |
| 8 | MPBV075-C | Blending valve | Buy online |
| 9 | DZSW24-C | Blending valve insert | Buy online |
| 10 | MPPT-C | Blending valve head | Buy online |
| 11 | OMFV-C | Pin section | Buy online |
| 12 | ALE075/14-C | Nut/olive | Buy online |
| 13 | WPEX/xx-C | Tube | N/A |
| 14 | OMDA-C | Actuator | Buy online |
| 15 | OMDAC-C | Actuator collar | Buy online |
| 16 | GC14-C | Guide curves | Buy online |
| 17 | OMPG-C | Pressure gauge | Buy online |
| 18 | OMDS-C | Filing/flushing | N/A |
Apr 2007 – Aug 2009 – Stainless steel manifolds (OMSxx-C)
| No. | Code | Description | Buy online |
| 1 | PM1-A | Complete pump module | N/A |
| 2 | BVM1/F1(R)-C | Valve (blue) | N/A |
| 3 | OMSFG-C | Flow gauges | Buy online |
| 4 | OMSTG-C | Temperature gauge | Buy online |
| 5 | OMSVV-C | Air vent | N/A |
| 6 | OMSPV-C | Filing/flushing | Buy online |
| 7 | OMSPG-C | Pressure gauge | Buy online |
| 8 | OMSB-C | Brackets | N/A |
| 9 | ALE075/14-C | Nut/olive | Buy online |
| 10 | Pin section | N/A | |
| 11 | UJ14-A | PEX couplers | Buy online |
| 12 | OMDA-C | Actuator | Buy online |
| 13 | OMDAC-C | Actuator collar | Buy online |
| 14 | BVM1/F1(B)-C | Valve (blue) | N/A |
| 15 | M1/28-C | 1″ – 28mm compression | N/A |
| 16 | BC-C | Blanking cap (for ports) | Buy online |
| 17 | BV3/4B-C | Valve (blue) | N/A |
| 17a | BV3/4R-C | Valve (red) | N/A |
| 18 | GC14-C | Guide curves | N/A |
| 19 | 3/4MI22-C | 3/4″ – 22mm compression | N/A |
| 20 | G1560-C | Pump | N/A |
| 21 | PM-C | Pump module/blending valve | N/A |
Aug 2009 – Oct 2010 – Brass plated manifolds (OMExx-C)
| OME Manifold | |||
| No. | Code | Description | Buy online |
| 1 | PM1-A | Complete pump module | N/A |
| 2 | OMEFM-C | Flow gauges | Buy online |
| 3 | OMETG-C | Temperature | N/A |
| 4 | OMSVV-C | Air vent | N/A |
| 5 | OMEAV-C | Air vent | N/A |
| 6 | OMSPG-C | Pressure gauge | Buy online |
| 7 | OMEDV-C | Filing or flushing | N/A |
| 8 | ALE075/14-C | Nut/olive | Buy online |
| 9 | OMEPV-C | Pin section | Buy online |
| 10 | OMDA-C | Actuator | Buy online |
| 11 | OMDAC-C | Actuator collar | Buy online |
| 12a | BVM1/F1(B)-C | Valve (blue) | N/A |
| 12b | BVM1/F1(R)-C | Valve (red) | N/A |
| 13 | M1/28-C | 1″ – 28mm compression | N/A |
| 14a | BV3/4B-C | Valve (blue) | N/A |
| 14b | BV3/4R-C | Valve (red) | N/A |
| 15 | UJ14-C | Joiner | N/A |
| 16 | GC14-C | Guide curves | N/A |
| 17 | 3/4MI22-C | 3/4″ – 22mm compression | N/A |
| 18 | G1560-C | Pump | N/A |
| 19 | PM-C | Pump module/blending valve | N/A |
Oct 2010 – Present – Stainless steel manifolds (OMSxx-C)
| No. | Code | Description | Buy online |
| 1 | PM1-A | Complete pump module | N/A |
| 2 | BVM1/F1(R)-C | Valve (blue) | N/A |
| 3 | OMSFG-C | Flow gauges | Buy online |
| 4 | OMSTG-C | Temperature gauge | Buy online |
| 5 | OMSVV-C | Air vent | N/A |
| 6 | OMSPV-C | Filing/flushing | Buy online |
| 7 | OMSPG-C | Pressure gauge | Buy online |
| 8 | OMSB-C | Brackets | N/A |
| 9 | ALE075/14-C | Nut/olive | Buy online |
| 10 | Pin section | N/A | |
| 11 | UJ14-A | PEX couplers | Buy online |
| 12 | OMDA-C | Actuator | Buy online |
| 13 | OMDAC-C | Actuator collar | Buy online |
| 14 | BVM1/F1(B)-C | Valve (blue) | N/A |
| 15 | M1/28-C | 1″ – 28mm compression | N/A |
| 16 | BC-C | Blanking cap (for ports) | Buy online |
| 17 | BV3/4B-C | Valve (blue) | N/A |
| 17a | BV3/4R-C | Valve (red) | N/A |
| 18 | GC14-C | Guide curves | N/A |
| 19 | 3/4MI22-C | 3/4″ – 22mm compression | N/A |
| 20 | G1560-C | Pump | N/A |
| 21 | PM-C | Pump module/blending valve | N/A |
If you need any further support, you can contact our Technical Support Team via techsupport@nu-heat.co.uk or 01404 540745 between 8am and 5pm, Monday to Friday.
Can’t find what you’re looking for?
You can contact our Technical Support Team or give them a call between 8am and 5pm, Monday to Friday.