fuel burning heater turning on when it shouldn't

[Rick-sta]

Evening all,

My fuel burning heater has been acting a bit odd lately. I've noticed over the last few weeks that it keeps turning on when it shouldn't. Many times now it has turned on automatically when outside temperature is reading above 5oc, and I've also had it turn on many times whilst the engine temp is already up to running temp (over 80oc).

When it's running it seems to be running fine. although I'm not sure if it's running as effectively as before, as quite a few times when I've turned it on remotely in the morning the car hasn't been as warm as usual (I have the pre-heater set up with the interior heaters running). I'm not sure if this is just due to the extra cold weather we've had recently.

The fuel burning heater also seems to be louder than usual.

Any ideas? I had the pcb repaired just over a year ago.

Cheers,

[Lotaskin]

Originally Posted by Rick-sta

Evening all,

My fuel burning heater has been acting a bit odd lately. I've noticed over the last few weeks that it keeps turning on when it shouldn't. Many times now it has turned on automatically when outside temperature is reading above 5oc, and I've also had it turn on many times whilst the engine temp is already up to running temp (over 80oc).

When it's running it seems to be running fine. although I'm not sure if it's running as effectively as before, as quite a few times when I've turned it on remotely in the morning the car hasn't been as warm as usual (I have the pre-heater set up with the interior heaters running). I'm not sure if this is just due to the extra cold weather we've had recently.

The fuel burning heater also seems to be louder than usual.

Any ideas? I had the pcb repaired just over a year ago.

Cheers,

I think the first things I would look at is the temperature sensor and for any chafing to earth of the signal wire from your GSM switch to the FBH.

[Dragrad]

Thread moved to a more appropriate forum. Re-direct left in old. This may be the better forum as threads get ‘lost’ very quickly in the General Forum.

[David Lawrence]

Originally Posted by Lotaskin

I think the first things I would look at is the temperature sensor and for any chafing to earth of the signal wire from your GSM switch to the FBH.

K-line noise from the car can cause some erratic triggering of the fbh and many of us have cut the red/white wire in the 6 pin plug to prevent it. This causes no impact at all in the operation of the fbh other than that so quite safe to do. Just make sure to tape up the cut ends to keep them insulated.

However, the fbh turning on when coolant temperature appears to be high is not in itself un-usual. If the temperature switch behind the bumper has activated due to low outside air temp, then it turns the fbh on, and once it has had a full burn cycle and got the temperature of the water up to about 73 degrees, then it will keep cycling back on every time the coolant drops again, which in cold days can happen quite often as the engine doesnt generate so much heat to keep the coolant temperature so high especially when running a lot of very cold outside air over the radiator at speed in winter.

Check if your k wire is cut, and if not i would cut it, if already cut then i would imagine it is working as it should because it is cold outside.

[Rick-sta]

Originally Posted by David Lawrence

K-line noise from the car can cause some erratic triggering of the fbh and many of us have cut the red/white wire in the 6 pin plug to prevent it. This causes no impact at all in the operation of the fbh other than that so quite safe to do. Just make sure to tape up the cut ends to keep them insulated.

However, the fbh turning on when coolant temperature appears to be high is not in itself un-usual. If the temperature switch behind the bumper has activated due to low outside air temp, then it turns the fbh on, and once it has had a full burn cycle and got the temperature of the water up to about 73 degrees, then it will keep cycling back on every time the coolant drops again, which in cold days can happen quite often as the engine doesnt generate so much heat to keep the coolant temperature so high especially when running a lot of very cold outside air over the radiator at speed in winter.

Check if your k wire is cut, and if not i would cut it, if already cut then i would imagine it is working as it should because it is cold outside.

The K wire hasn't been cut on mine at the moment, but I think you're right about the fuel burning heater turning on when the temperature appears to be high. I have a working thermostat so the running tem is staying at around 82-84oc (on the digital temp gauge), however when in traffic it has been dropping in this cold weather and once went as low as 72oc. So this will probably explain why I keep hearing the fuel burning heater turn on.

However, yesterday I came across another problem. the fuel burning heater was running during my drive home, when I arrived and parked up on the driveway I noticed quite a fog/mist across the front of my car. Opened up the bonnet and the fuel burning heater was pushing a lot of smoke out of the exhaust. This was at 11pm at night so not sure what colour it was but when I shined the led light from my phone the smoke looked very clear with maybe a hint of blue to it.

it's never done this before until now. I've only had the fuel burning heater fitted for just over a year, and when fitted I took the whole thing apart to clean it out and also had the pcb board repaired.

[FrenchMike]

Hi Rick,i think your burner works perfectly .
generally it's the contrary ;seeing that they are stuffed with Securities ,they refuse to start .

3 conditions to get a start :

-external temp less than 5 degrees +engine runnung+coolant temp lower
than 77 degrees .

Watch the coolant temp on the OBD in 7.0 for more accuracy


Mike

[trebor]

white smoke can mean unburnt fuel, could be a glowplug issue

[FrenchMike]

Originally Posted by trebor

white smoke can mean unburnt fuel, could be a glowplug issue

Nop ...service needed (check the air filter firstly)

[HarryM1BYT]

Originally Posted by trebor

white smoke can mean unburnt fuel, could be a glowplug issue

I agree, due to lots of diesel mist/ unburnt fuel in the exhaust. You should be able to smell it too.

Service the combustion chamber again and more thoroughly.

[bl52krz]

I went out the other day when the temperature was only 2deg all day. The FBH was still on when I got back home after a 20 mile run. This is normal according to the manual. As said above, FBH cycles on and off. There is a 'running' cost of diesel while it is running on full burn, and when cycling on/off the diesel cost is much less until it shuts off.