First up was an early Potterton Netaheat Profile, probably the best gas boiler Potterton ever made. Sadly discontinued in 2005. The boiler was immaculate inside, looking no different inside at 30 years old from how it would have looked at 3 years old. I didn’t get any photos as my customer was one of those fascinated to see inside of their boiler and was at my side nearly all the time asking a thousand questions. We talked constantly as I gave a running commentary on what I was doing and frankly, I just forgot about photos!
Anyway, the fault was that the fan ran, the spark sparked and the pilot flame lit. Then the spark stopped but the boiler did not progress to lighting the main burner as it should have. The spark stopping is a strong indication the PCB has detected the presence of the flame so failure of the gas valve to open the gas supply to the main burners suggests an open circuit main burner solenoid coil. Sure enough on measuring the resistance, I found it was open circuit instead of the correct value of 5kOhms approx. I fitted a new solenoid coil and the boiler worked perfectly once again, then I completed the statutory safety checks and wrote out my bill. Customer paid for the repair and I was on my way. The whole visit took perhaps 45 minutes.
Next up was the same make and model of boiler, but in one of the villages south of Reading. An old customer who’d used me seven or eight years ago and remembered my trading name Mike the Boilerman, then Googled that to track me down. This chap had been persuaded to have smart meters fitted and after fitting the smart gas meter, the boiler no longer worked on testing, so the meter man shrugged shoulders and left. Great! Some testing just by turning on and off the two channels on the programmer (heating and hot water) revealed the boiler did actually light correctly when the hot water channel was set to ON. The failure was only present when the heating channel alone was set to ON – the boiler would not light. This suggested the diverter valve in the airing cupboard (next to the hot water cylinder and pump) was not moving across to the heating position which is a common failure, the electric motor inside them stops working and needs replacing. Closer investigation found this was not the fault though, the motor was moving the valve across to the correct position. Once in the correct position a microswitch inside the valve sends a “Call for Heat” signal to the boiler telling it to light but on this customer’s valve that signal was missing, indicating a failed microswitch. The microswitch is not easily replaced so I fitted a whole new motor head which resolved the problem and the heating now worked perfectly. Customer paid my bill and we had a fairly long chat about bread making, a hobby we share, when I noticed some of the things used for bread-making around in the kitchen. Ok, it was a breadmaker!
Third was a landlord whose tenant had no hot water in their town centre flat in Reading. He texted me in the morning having found my website by Googling for “Gledhill Reading”, and landing on my old website called “Gledhill Repairs” (www.gledhill-repairs.co.uk). His flat in Reading has a Gledhill Pulsacoil thermal store, which I’m thoroughly familiar with and keep a stock of parts for in the van. Anyway fortunately, his tenant was working from home today so I visited and once again, this was a quick repair to complete.
The appliance is an electric hot water thermal store and neither heater element was working, because both thermostats (one in each heater) had tripped. This happens when the lower thermostat fails in the ON condition and the overheat protection steps in to disconnect. When both together trip, this indicates the lower thermostat is the faulty one as the upper thermostat gets over-heated too, by the lower heater not turning OFF when up to the correct temperature. So a new lower thermostat and re-setting of the upper fixed it for this landlord and tenant. One slight problem with this repair is after fixing it, the appliance is still cold so no testing and proving the hot water now works is possible. The only way is to wait an hour while the unit warms up. I knew the water was warming up as my meter proved the upper element was drawing power but the tenant was looking faintly doubtful, so I gave them my phone number and asked them to call me in an hour if still no hot water. No phone call so I’m imagining it all is working fine now! More about Pulsacoils on my site www.pulsacoil-repairs.co.uk
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