I’ve got a Ferroli (OFER) Falcon combi boiler, fitted just over a year ago – out of warranty.
Recently the Domestic Hot Water supply has been a problem – the hot water will not run consistently hot. I’ve checked the boiler in the loft, and when this problem is occurring it appears that the boiler fires up after a few seconds 9the burner on indicator lights) – as usual – but cuts off for a few seconds, this pattern continues indefinitely. Therefore the water keeps going cold.
When the hot water is OK the ‘Burner On’ indicator stays on when the hot tap is running.
The ‘power supply’ and ‘domestic hot water on’ indicators on the front panel are both on in both states.
I’ve checked the fault finder booklet and it says that if the DHW sensor is on and the water does not heat, the problem is the DHW sensor.
What I want to know is, does it sound like it’s just a new DHW sensor required, or could it be something else, and why has it failed so soon. ALso, is this expensive to fix?
The problem is usually related to flow. Turning a burner on that is large enough to heat a house to heat a cup of water makes the burner control cycle rapidly. Run the water with enough volume to use the 100,000 btuh so you can see if the water temperature becomes steady at the largest volume. If the problem occurs with small quantities, that is something manufacturers of these devices need to overcome.
Probably wouldn’t be too expensive but I’m not familiar with that brand so I don’t know how much the parts might cost. Sounds as if it needs to be looked at in case the sensors ARE working but pointing to another problem.