Fault Finder

This check list has been designed to help you understand your heat recovery ventilation system and give you tips on what to look for if issues arise.

If you are worried about your system, please carry out the following checks:


Fault	Cause	Remedy
Unit won’t switch on	Electrical Fault	Switch off the mains and
		a) check power supply to switched fused spur
		or b) check fuse or check electrical connector at unit
		or c) check wiring to controller
Unit trips out	Water build up in unit	a) check that unit is inclined to drain connection
		or b) check condensation pipework for blockage
		or c) check for earth fault on wiring to controller/control switch/unit
		or d) check for motor thermal fuse trip by switching off unit, allowing
		to stand for approx 45 minutes then restarting unit
		or e) ensure condensate pipe is insulated, if positioned in an area prone
		to freezing
Low airflows at terminal devices	1) Flexible silencer crushed or collapsed internally	1) Replace flexible silencer
	2) Excess fouling of heat exchanger	2) Service the unit
	3) Fresh air / exhaust air devices blocked	3) Disconnect ducting and remove debris
	4) Filter (if fitted) blocked	4) Replace filter
Air flow failure	Fan / fans stopped	Switch off the mains electrical supply to the unit and
		a) remove access panel and heat exchanger
		b) check fans for free operation
		c) replace if seized
Noise at air terminal devices	1) Excessive airflow	1) Check airflow rate complies with commissioning data.
	2) Fan/Fans bearing failure	2) Switch off the mains electrical supply and remove access panel
		and heat exchanger. Check fans individually for evidence of
		bearing noise, replace if considered excessive.
Noise from unit	1) Unit not located on acoustic mat	1) Lift unit and fit acoustic mat
	2) Fan/Fans bearing failure	2) Switch off the mains electrical supply and remove access panel
		and heat exchanger. Check fans individually for evidence of
		bearing noise, replace if considered excessive.