So I moved into a house with a Potterton Suprima 70 L about 7 years ago, never really fiddled with the heating much as it just seemed to work on auto when required and be "off" in summer, hot water was always hot, great times. Those ended earlier this summer when the hot water ran out, boiler wouldn't fire after running the blower for about 7 seconds, turned immersion on and started troubleshooting.
Having never looked at a boiler before I was a bit out of my depth and spoke to a local plumber & gas engineer who had done work on a number of houses built at the same time with the same boilers, he popped round and did some bits, checked the air pressure sensor and it seemed ok (listened for the click I assume as didn't have a multimeter) and suggested swapping the PCB, I'd seen the new ones were nearly £300 do picked up a refurb for £70, this didn't solve it, no gas, no spark.
I kept on trying bits and after probing around with the multimeter for a while I discovered the mod to add the water flow sensor in series with the airflow sensor, this appeared to be the issue, discovered there's a pump behind the laundry rack the previous owners had installed which had seized, popped that off and disassembled and graunched as much iron grit out of it as I could and it now runs a treat, boiler instantly fired up which was exciting with half the covers off!
Fast forward a couple of hot summer days and I'm in the kitchen and realise the boiler is happily cracking on despite the hot water demand being off from the danfoss thermostat?! There's another danfoss box up in the hot water tank cupboard - is that likely to be it's power switch with fuse above the immersion switch? Anyway what do I need to do to fix the demand side? both Potterton PCB's seem to work fine, unless they've both failed in this exact same way? I'm more suspicious that after being turned off for a couple of weeks something has happened with the danfoss?
Having never looked at a boiler before I was a bit out of my depth and spoke to a local plumber & gas engineer who had done work on a number of houses built at the same time with the same boilers, he popped round and did some bits, checked the air pressure sensor and it seemed ok (listened for the click I assume as didn't have a multimeter) and suggested swapping the PCB, I'd seen the new ones were nearly £300 do picked up a refurb for £70, this didn't solve it, no gas, no spark.
I kept on trying bits and after probing around with the multimeter for a while I discovered the mod to add the water flow sensor in series with the airflow sensor, this appeared to be the issue, discovered there's a pump behind the laundry rack the previous owners had installed which had seized, popped that off and disassembled and graunched as much iron grit out of it as I could and it now runs a treat, boiler instantly fired up which was exciting with half the covers off!
Fast forward a couple of hot summer days and I'm in the kitchen and realise the boiler is happily cracking on despite the hot water demand being off from the danfoss thermostat?! There's another danfoss box up in the hot water tank cupboard - is that likely to be it's power switch with fuse above the immersion switch? Anyway what do I need to do to fix the demand side? both Potterton PCB's seem to work fine, unless they've both failed in this exact same way? I'm more suspicious that after being turned off for a couple of weeks something has happened with the danfoss?
