Hi,

I have been repairing circuit boards for a few years and a plumber friend has come to me in the hope I can fix a few of the faulty boiler boards he has laying around. He tends to send them to ewaste but I'm sure they're easily fixed.

I've searched Google and a few forums but can't seem to find any information on creating a setup for diagnosis and testing. There are people that fix the boards though so I know it can be done.

He's offered to give me a boiler, I won't be connecting it to gas or water so wonder if there's a way to trick the board into thinking everything is connected as normal? For example; the pressure sensor at start up, would just need a variable resistor or potentiometer which I change to make the board think the pressure is rising, right?

Are there any tutorials or information from other people that have done this? Can anyone please help?

I'm in the UK (not sure if boilers are the same in the rest of the world)

 

What you need is the installation guide and diagnostic section for the installation. And get the circuit that shows how it is connected to the boiler installation.
You will need a couple of variable resistors to simulate the resistive temperature sensors, and automotive light bulbs, 2 in series, to simulate the solenoid valves. And probably a 24 volt transformer to power them. And some switches to simulate the various sensor switches in a boiler system..
But once you get the simulation bench set up then you can do the checks and see what fails to function. With a $100 per each repair charge you can easily make a few hundred every evening once you get the drill down.
Many of the boiler companies will give you a detailed description of how their system works and why it is the very best of all. So that is how you learn what must be done and what must happen.

 

What you need is the installation guide and diagnostic section for the installation. And get the circuit that shows how it is connected to the boiler installation.
You will need a couple of variable resistors to simulate the resistive temperature sensors, and automotive light bulbs, 2 in series, to simulate the solenoid valves. And probably a 24 volt transformer to power them. And some switches to simulate the various sensor switches in a boiler system..
But once you get the simulation bench set up then you can do the checks and see what fails to function. With a $100 per each repair charge you can easily make a few hundred every evening once you get the drill down.
Many of the boiler companies will give you a detailed description of how their system works and why it is the very best of all. So that is how you learn what must be done and what must happen.

Thank you, that's great help

 

Most combustion-based heating systems have similar functions, even though the hardware can be quite different.Most high efficiency furnaces have at least one blower, whose operation must be verified by a switch or sensor, and mostly a pilot burner that must have a gas valve operated and an ignition source, so there are two outputs plus a sensor to verify the pilot flame is lit. Then there is at least one main gas valve that is operated when all of the conditions are right. After that the blower gets switched on when the air heating portion is hot enough, and sometimes a humidifier output will switch on the humidifier system. So there would be quite a few indicators and switches to simulate the several sensors.
The test panel would not need to be terribly expensive, but there would be a lot of wires to connect.

 

I would download the service manual for that boiler or other types like Vailant, Baxi, Worcester etc, and see what the inputs are , then start from there.

 

I would download the service manual for that boiler or other types like Vailant, Baxi, Worcester etc, and see what the inputs are , then start from there.

Always a good choice, getting a service manual. Not always possible, though, because some companies do not want "outsiders" servicing their products.

 

Vailant and Worcester installation manuals are available online free pdf download.