Member Since: 20 Mar 2018
Location: Lancashire
Posts: 105
Error 0xAB - "overheat sensor interruption"
Hi,
My FBH used to work flawlessly and as the nights are getting colder I decided to just double check that all was still ok.
Alas, it isn't My Thermocall unit failed to start it remotely with "Unknown error" so I dug out the diagnostic cable and installed ThermoTest to see if I could track down the issue.
It had a lockout and the fault AB stored.
I cleared it and tried starting it from ThermoTest and it seems as soon as the fuel pump cuts in it then immediately faults out with the same error.
I tried multiple times, including giving it a blow job just in case....
Using ThermoTest to control everything seems to work individually, although when the fuel pump is turned on the same fault gets logged.
Is there a temperature sensor on the actual fuel pump? Which overhear sensor does it refer to? The temperature displayed in ThermoTest is between 35C and 42C
Hoping someone can help!!
12th Oct 2021 11:45 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4626
Yeah there are two sensors on a single section of loom within the heater. One is a temp sensor and the other an "overheating" sensor to protect from anything silly occurring!
They can be purchased as spare part replacements and are not difficult to fit. They are a "button" type sensor and are "push fit" located on the side of the heat exchanger. With the cables routed in the casing wall back to a single plug at the PCB. I think you might be able to replace them with the burner in situ, but to be honest I can't remember, and so maybe it's worth considering disassembly and a clean while you're fitting new sensors.
I might have a visual description/manual somewhere if I can find it.
In the meantime have a look at the link below and you can see TTV sensors for VW, but check with the vendor that they are the same for LR, or PM member Motolab on here. https://www.prokes-auto.com/kategorie/thermo-top-v-532168-3/yµ (idµ - eAµ) ψ=mψ
13th Oct 2021 1:26 am
ibruceuk
Member Since: 20 Mar 2018
Location: Lancashire
Posts: 105
Brilliant thanks!
I'll get on with stripping it down then
15th Oct 2021 11:12 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4626
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My Thermocall unit failed to start it remotely with "Unknown error" so I dug out the diagnostic cable and installed ThermoTest to see if I could track down the issue.
