Webasto air top 5000 - Fault finding

[symondo]

I've had a search around the forum and found the thread with the fault codes in.

Here's where I'm at just now;

Heater turns on, looks to take on diesel - makes the right noises - can feel it drawing from the pipe - although Ive not checked supply (i can see it is in the on position)

after about 3 or 4 minutes - it makes all the noises id expect - fans etc...

Now - the air intake - feels as if there is air being drawn in
The exhaust has air leaving - all be it cold?
The unit doesn't heat up - but blows cold air into the cabin - i can even hold the exhaust pipe.

There is a smell of diesel from the unit while it operates.

With the fault code showing as 1 flash to 5 fast flashes.

The batteries are showing a charge of 14v when i have turned this unit on.

From reading up on the fault code i looks to be a number of things which seem quite straight forward however i see no way of taking the unit apart to check sensors or the glow pin?

Can anyone advise on my findings or give an indication? My head is saying the glow pin isn't doing its thing.

 

[BlueChip]

I've had a search around the forum and found the thread with the fault codes in.

Here's where I'm at just now;

Heater turns on, looks to take on diesel - makes the right noises - can feel it drawing from the pipe - although Ive not checked supply (i can see it is in the on position)

after about 3 or 4 minutes - it makes all the noises id expect - fans etc...

Now - the air intake - feels as if there is air being drawn in
The exhaust has air leaving - all be it cold?
The unit doesn't heat up - but blows cold air into the cabin - i can even hold the exhaust pipe.

There is a smell of diesel from the unit while it operates.

With the fault code showing as 1 flash to 5 fast flashes.

The batteries are showing a charge of 14v when i have turned this unit on.

From reading up on the fault code i looks to be a number of things which seem quite straight forward however i see no way of taking the unit apart to check sensors or the glow pin?

Can anyone advise on my findings or give an indication? My head is saying the glow pin isn't doing its thing.

I can see a slight dimming of my saloon lights as the glowplug pulses, that might give you a clue if yours is not working

 

[Vara]

On my set up you can see the glow plug kicking in and out on the battery monitor.

 

[symondo]

there is definately no dimming of lights

I think the glow plug wil lbe my first port of call...

So... how to you get to it and is it a common part to lay my hands on for a replacement?

 

[Vara]

Manual here;

http://www.suremarine.com/manuals/webasto-repair-manuals/at3500st-at5000st-repair.pdf

Personally I'd get an expert to do it.

 

[symondo]

Many thanks Vara

I do like to try and understand possible causes incase its something that i am capable or resolving before calling on someone whos going to cost me a potential small fortune. I'll have a careful read of that and see if its something i think i can attempt.

 

[David2452]

Many thanks Vara

I do like to try and understand possible causes incase its something that i am capable or resolving before calling on someone whos going to cost me a potential small fortune. I'll have a careful read of that and see if its something i think i can attempt.

If the glowpin or its associated cable were faulty there would be a different flash code, the code you have is pretty meaningless in many respects as it is simply fail to start, you already knew that. As there are no other codes my money is on a coked up burner which will require at least a good clean, I use a heated ultrasonic bath to get the rest out after a mechanical clean. Frequently the best approach is simply a new burner cartridge. Any sensor faults would also show different codes.

 

[symondo]

If the glowpin or its associated cable were faulty there would be a different flash code, the code you have is pretty meaningless in many respects as it is simply fail to start, you already knew that. As there are no other codes my money is on a coked up burner which will require at least a good clean, I use a heated ultrasonic bath to get the rest out after a mechanical clean. Frequently the best approach is simply a new burner cartridge. Any sensor faults would also show different codes.

is this something you would recommend to someone with some limited skills?
Im not shy of a set of spanners but im no mechanic

 

[David2452]

is this something you would recommend to someone with some limited skills?
Im not shy of a set of spanners but im no mechanic

Actually taking the thing apart is not a problem if using the manual, however there is the need to recognise whether a good clean or a new burner is needed otherwise you will be back to sqare one it a short time. It is easy to check the glowpin once its disconnected using a decent multimeter and the values are all in the manual. There are two types of burner used on AT5000s which have a ceramic glowpin (not plug) that also doubles as a flame sensor so that resistance value at the correct temperature will need to be checked too. If the heater is five or six years old I would just get a new burner cartridge and pin if I were you, you will not know which type until you strip it, or if you PM me the serial # I can tell you which type it is. If you are in any doubt that you can do it yourself then whip it off and drop it into your local Webasto agent.

 

[symondo]

Right - sounds a little daunting but in for a penny and all that...

I'll have a good read up and see if i can locate any numbers on it at my next visit to the boat. Im unsur where our webasto agent would be - we are the west coast of the highlands of scotland - so usually its a postal effort and pass to our local engineer to sort if we cant.

 

[David2452]

Just go to the Webasto site and enter your postcode and it will bring up the nearest service agent to you.

 

[symondo]

i had a thought on this heater cartridge you mention....

are they unit specific? I ask because i remember from the older boat we had - there was a 24v Webasto fitted which we removed to fit a 12v Erberspacher.
This is still in the house. I'd assume anything to do with the glow plug wouldnt be a goer as it'd be matched as the wrong voltage, but without knowing what is involved in the part you have mentioned - is it possible they maybe compatible?

 

[David2452]

i had a thought on this heater cartridge you mention....

are they unit specific? I ask because i remember from the older boat we had - there was a 24v Webasto fitted which we removed to fit a 12v Erberspacher.
This is still in the house. I'd assume anything to do with the glow plug wouldnt be a goer as it'd be matched as the wrong voltage, but without knowing what is involved in the part you have mentioned - is it possible they maybe compatible?

Yes they are unit specific, assuming your old unit is an AT3500 or AT5000 you may be lucky as they have the same burner, but there was a change of burner and burner tube design during the production of these heaters, if yours differ you may have to swap over the burner and tube. As you have deduced, the glowpin will be of no use at all and if the current one is coked up you may not get it out without damaging it so would have to get a new one.