Logic Combi 24 - PCB keeps blowing

[bernardgreen]

The PCB industry is amazingly uninterested in the reliability of their products.

The PCB "industry" involved with supplying PCBs to boiler manufacturers may not "have an interest" in reliability. Or more probably they are not required to have an interest.

In general the PCB industry that is not involved with boiler controls does have an interest in reliability and quality pf the products it produces.

The failures due to over sized holes in the Suprima 80 PCB was pointed out to the manufacturer several years ago. They were already changing the design to remove the connectors and solder the loom directly to the PCB and then clamp the loom to the PCB to provide strain and vibration relief.

 

[DaveHerns]

Next time it fails ,ask to keep the old PCB and get someone to check it out. Maybe a lot of failed PCBs are sold on to companies who remanufacture them and sell them as refurbished. I have a refurbed PCB in my boiler and it's lasted longer than 2 genuine boards so maybe the remanufacturers identify the shortcomings ? Didn't fit it myself before anyone asks, job done by a local chap who has a business selling "recycled" boiler parts.

 

[vulcancontinental]

Does it do it after a heavy rainfall or rain with strong wind by any chance ?

Good call. Also, are you rural or country? Most power surge protection I was told will not stop a voltage spike which is more common in the countryside. Fuses protect against current. A Honeywell tech told me a monitor was put on a domestic house in Berkshire any years ago to record the electricity supply; can't remember if if was 7 or 17 times that year the voltage exceeded 1000V. The electricity supplier denied it then they rolled out the sheet.

 

[bernardgreen]

I have a refurbed PCB in my boiler and it's lasted longer than 2 genuine boards so maybe the remanufacturers identify the shortcomings ?

Some do. Where connector pins are a loose fit in the PCB they can re-make the joint adding a loop of tinned copper round the pin and then a few millimetres along the track. A blob of PCB cement adds mechanical strength.