Tag Archives: Boiler

Miswired Boilers?

or not?

So we’re almost a year in to our new home, and it’s come time to get the boiler serviced. The heating has been working fine since a faulty pressure vessel was replaced a few months ago.

We decided to use the same engineer that replaced the pressure vessel to service the system as he seemed knowledgeable and thorough, whereas PRS (who installed the system) failed to diagnose and fix it when they were sent out in the first instance.

We’ve also received a letter from the NHBC about a British Gas deal, but we’d already booked the service by that point.

The big finding was that the system hasn’t been wired up correctly. Specifically, the heating pump has not been connected to the boiler wiring, but to the thermostat/valve wiring.

This means when the thermostat switches, the pump stops immediately, whereas it should continue to run for a number of minutes via a bypass circuit, so that the water in the circuit can cool down rather than just sit in the boiler. (A bit like the cooling fan on a car continues to run after the engine is switched off)

Whilst the system functions normally, it will, over time, shorten the life of the boiler and void the warranty as it hasn’t been installed according to Ideal Boiler’s installation instructions.

Kevin, the engineer,  found this partly as he was being thorough when testing, but also saw a taped off wire in the boiler casing and wondered what it was needed for.

As all the systems across the development were installed by PRS to more or less the same spec, I would not be surprised if there are others out there like this.

You could quickly check, by turning the upstairs thermostat up high, wait for the radiators to heat up fully, then turn the thermostat back down. You should hear the valves close but the pump should stay running and shutdown after a number of minutes.

Otherwise, we can’t recommend Kevin from Personal Home Care highly enough to service and check your system. (i’d also note the British Gas offer only covered the boiler, not the Hot Water Cylinder, for which Kevin is the manufacturer certified agent and how he was sent to see us originally)

Update:- 4 June, The electrician from Renelec has been out and rewired the pump correctly. Took about 30mins in all, as the cabling was already in the walls.