Which Thermostat!! - 1800 BMC Thornycroft

[christophert]

Evening all :-)

I have an 1800 BMC Thornycroft engine, and as the temperature gauge and the oil pressure gauge are not working, I thought I'd start with the obvious and replace the sensors/switch and the thermostat, so went searching.

There are more than one type of thermostat - a 74 degree and an 82 degree. To complicate matters further, 74c Standard type without shut off and 82c with bypass shut off disc ??

 

I just wanna buy a thermostat! Now I'm confused... then that's easily done

Edited October 17, 2016 by christophert

[christophert]

Has anyone had any experience with this? Or has anyone any suggestions. Many thanks

[ditchcrawler]

Changing the thermostat wont make the gauge work. Get in there with a meter and find out where the volts have gone. The way you are going you could replace the whole engine and they still wouldn't work.

[christophert]

Changing the thermostat wont make the gauge work. Get in there with a meter and find out where the volts have gone. The way you are going you could replace the whole engine and they still wouldn't work.

A meter thingy!! With numbers and stuff ! erm ... ok. The thing is, 'cos the engine is so old, built around nineteen canteen and made from wood and stone, I thought it'd be good to have a spare thermo anyway.

Edited October 17, 2016 by christophert

[alan_fincher]

The general recommendation is to use an 82 degree stat if you have no calorifier, but only a 74 degree one if you do, to stop the domestic water being heated too hot. However I would say you can use the higher temperature stat with a calorifier, provided it has a themostatic mixer valve that limits how hot the water to the taps and showers are, by mixing in enough cold.

 

In my own experience a BMC 1800 needs the bypass type stat, with the extra disk on, and if you use the wrong type on a system that requires it you will have problems. However maybe not every 1800 needed or used the bypass stat, I'm not sure. If when you have the stat out, and peer down the housing it has a hole at the bottom with a flat seat around it for that extra bit of the stat to close down on to, then that's what you need. No hole at the bottom, then you mustn't try fitting a bypass stat

 

However none of this has anything at all to do with a temperature gauge not working, as has already been pointed out.

[ditchcrawler]

Evening all :-)

I have an 1800 BMC Thornycroft engine, and as the temperature gauge and the oil pressure gauge are not working, I thought I'd start with the obvious and replace the sensors/switch and the thermostat, so went searching.

There are more than one type of thermostat - a 74 degree and an 82 degree. To complicate matters further, 74c Standard type without shut off and 82c with bypass shut off disc ??

 

I just wanna buy a thermostat! Now I'm confused... then that's easily done

Duplicate post, reported.

[christophert]

The general recommendation is to use an 82 degree stat if you have no calorifier, but only a 74 degree one if you do, to stop the domestic water being heated too hot. However I would say you can use the higher temperature stat with a calorifier, provided it has a themostatic mixer valve that limits how hot the water to the taps and showers are, by mixing in enough cold.

 

In my own experience a BMC 1800 needs the bypass type stat, with the extra disk on, and if you use the wrong type on a system that requires it you will have problems. However maybe not every 1800 needed or used the bypass stat, I'm not sure. If when you have the stat out, and peer down the housing it has a hole at the bottom with a flat seat around it for that extra bit of the stat to close down on to, then that's what you need. No hole at the bottom, then you mustn't try fitting a bypass stat

 

However none of this has anything at all to do with a temperature gauge not working, as has already been pointed out.

Thank you, Alan ... A calorifier! Just off to google, back in a while

The general recommendation is to use an 82 degree stat if you have no calorifier, but only a 74 degree one if you do, to stop the domestic water being heated too hot. However I would say you can use the higher temperature stat with a calorifier, provided it has a themostatic mixer valve that limits how hot the water to the taps and showers are, by mixing in enough cold.

 

In my own experience a BMC 1800 needs the bypass type stat, with the extra disk on, and if you use the wrong type on a system that requires it you will have problems. However maybe not every 1800 needed or used the bypass stat, I'm not sure. If when you have the stat out, and peer down the housing it has a hole at the bottom with a flat seat around it for that extra bit of the stat to close down on to, then that's what you need. No hole at the bottom, then you mustn't try fitting a bypass stat

 

However none of this has anything at all to do with a temperature gauge not working, as has already been pointed out.

Mine's just got a hot water tank, but I'll double check the thermo as recommended though

[DHutch]

Duplicate post, reported.

 

Topics merged. Title edited to remove block caps and add engine type.

 

 

Thanks

 

Daniel

[christophert]

 

Topics merged. Title edited to remove block caps and add engine type.

 

 

Thanks

 

Daniel

Thank you, new to this site and learning

How can I tell if my boat has a calorifier? From what I can see, it has a hot water tank and an immersion switch, the water can also be heated from the engine/

[David Mack]

Thank you, new to this site and learning

 

How can I tell if my boat has a calorifier? From what I can see, it has a hot water tank and an immersion switch, the water can also be heated from the engine/

Then it has a calorifier. Its just the boaty name for the hot water tank which can be heated by engine cooling water passing through a coil, in the same way a boiler heats a domestic hot water cylinder in a house.

[DHutch]

Thank you, new to this site and learning

 

No worries at all. Best of luck with the engine!

 

 

Daniel

[christophert]

Then it has a calorifier. Its just the boaty name for the hot water tank which can be heated by engine cooling water passing through a coil, in the same way a boiler heats a domestic hot water cylinder in a house.

Thanks, David. Now, just need to get my gauges working.