Heat Recovery Units
Heat Recovery Units Troubleshooting
Unit is not operating
There is a minimum air recovery temperature required for the system to operate. If the home is below 16 degrees, the unit cannot run and will remain in alarm. The surrounding temperature must be raised by alternative means before the system can begin running.
Has the isolator switch been accidentally turned off? Quite a common occurrence, as these units tend to be housed in cupboards that often double up as storage – switches can easily be knocked and turned off without knowing.
These units use a compressor. It may be possible that this has seized or not running and therefore the system will be unable to operate. Qualified engineers can initially test this, and a refrigerant engineer may be required to provide resolution.
Is there any demand? If the system has met either your hot water or heating temperature – it does not need to operate further until further demand is needed. Check your settings to confirm this.
Unit is noisy / noisier than usual
Some units may automatically increase fan speed because of a blocked filter or blocked / closed vent. Different manufacturers have pre-programmed alarms that can notify you of when filters should ideally be tended to. As a guide however, these should be cleaned every three months and then replaced annually during routine inspections of the system.
With vents – most commonly the exhaust recovery vent can sometimes wind themselves shut – if this occurs then the system cannot recover any air to operate. These should be easily identifiable and rectified simply by opening.
We’ve compiled some more specific issues related to manufacturer unit models in the links below, from our experience and available user manuals.
