resistance in components

[bassmonster]

This question is just for general knowledge and not asking on how to perform a particular task on on a boiler.

Do all the boilers have the same resistance in their components? for example will a working thermistors have a resistance between 1200-1300 ohms or does it vary between manufacturers?

If they are more or less the same, is there some kind of list with given resistance available for all components out there somewhere?

 

[Killy Bing]

There is a list kicking around somewhere

varies hugely by components

Thermistors are the main ones to check.
they come in NTC and PTC
thats negative/positive temperature coefficient
Positive has the resistance increase on temperature rise where as negative resistance will decrease as temperature rises
they are given values at say 25 degrees and 60 degrees
they are listed as say 7k or 10k resisters
never mix and match thermistors from boilers unless you know they are the same type.

Most you will come across are NTC as they are more reliable


If a component gives a resistance of 0 you can put money on it has gone open circuit and is goosed, dead giveaway on solenoids

 

[combo]

Do all boilers have the PCB do a preliminary check on the thermistors initial value prior to commencing the fan, pump sequence ?? If this is the case a list of thermisitor 'ranges' would be really useful for diagnostics. I imagine many a PCB has been replaced in error because of out of range sensors.

 

[gasmanrob]

There is a list kicking around somewhere

varies hugely by components

Thermistors are the main ones to check.
they come in NTC and PTC
thats negative/positive temperature coefficient
Positive has the resistance increase on temperature rise where as negative resistance will decrease as temperature rises
they are given values at say 25 degrees and 60 degrees
they are listed as say 7k or 10k resisters
never mix and match thermistors from boilers unless you know they are the same type.

Most you will come across are NTC as they are more reliable


If a component gives a resistance of 0 you can put money on it has gone open circuit and is goosed, dead giveaway on solenoids

Its in the gsr only forum

 

[bassmonster]

Its in the gsr only forum

looks like a few months wait for me then....:sad:

 

[combo]

If you know anyone in British gas, they usually get all the top manufacturer info regarding technical stuff. I only worked as a subbie on servicing whilst I was there, I was always trying to wangle a lappy off them.

 

[gasmanrob]

If you know anyone in British gas, they usually get all the top manufacturer info regarding technical stuff. I only worked as a subbie on servicing whilst I was there, I was always trying to wangle a lappy off them.

Thats where the list came from