Wallas Heater

[wazza]

We have a Wallas 1800 paraffin heater, its only a few years old and this year I renewed the ducting so it heated the boat better...
Anyway, working fine then suddenly after an hour or so we got a heavy smell of paraffin and it stops heating.
The motor is still blowing air(as in the cool down mode) but the heat slowly stops..
I turned it off, then back on again and the same thing happened an hour or so later again.
I have no thermostat and run it on full then some time later on half...

Any ideas why this sailor is cold...???

 

[earlybird]

I would look closely at the exhaust ducting, which is a flexible stainless-steel tube running inside the combustion air intake duct, both terminating at the co-axial external skin fitting. With the design and construction of the Wallas, there should be no way paraffin fumes should reach the cabin. The heat-exchanger is of stainless steel construction IIRC.
Can't explain the cooling down with any certainty, but the combustion process is fairly finely tuned, and may be reacting to imbalance in the air inlet/exhaust system.
Is the pump still operating, ie ticking, when the heater cools down? Is fuel flowing back to the tank along the return tube?
There is an overheat cut-out which switches off the pump, maybe your ducting mods. have caused this to operate, but this has to be re-set manually, so seems an unlikely cause.
The smell of paraffin is definitely wrong though.

 

[David2452]

Typical symptoms and the fact that you have just increased the duct length confirm it to a large degree. Wallas, especially the small ones do do not like too much ducting and overheat, some do not need a manual reset, only to be allowed to cool down. BTW, if its a few years old then its also time for a service

 

[wazza]

Typical symptoms and the fact that you have just increased the duct length confirm it to a large degree. Wallas, especially the small ones do do not like too much ducting and overheat, some do not need a manual reset, only to be allowed to cool down. BTW, if its a few years old then its also time for a service

I just changed the ducting size as I had an old Wallas before which had 90mm ducting & when I bought the Wallas 1800 there were 2 blow holes of 60mm instead of 1 of 90mm. So I haven't really increased..

Maybe a service is needed even though I haven't used it that much...

 

[David2452]

I just changed the ducting size as I had an old Wallas before which had 90mm ducting & when I bought the Wallas 1800 there were 2 blow holes of 60mm instead of 1 of 90mm. So I haven't really increased..

Maybe a service is needed even though I haven't used it that much...

I do have the fault diagnosis manual (proper dealer one not the handbook) if you would like it in PDF, if so drop me a PM. It does assume some knowlege of the Wallas poducts and possesion of some specialist equipment but is useful nonetheless.

 

[wazza]

I do have the fault diagnosis manual (proper dealer one not the handbook) if you would like it in PDF, if so drop me a PM. It does assume some knowlege of the Wallas poducts and possesion of some specialist equipment but is useful nonetheless.

Have sent you a PM, thank you...

 

[aquaplane]

I have one too, when you find out what was up can you let us know for future reference please?

I have the heater hung directly off the 2460 mushroom exhaust fitting so there is no ducting which I like.

 

[wazza]

I have one too, when you find out what was up can you let us know for future reference please?

I have the heater hung directly off the 2460 mushroom exhaust fitting so there is no ducting which I like.

If you have no ducting then how to you transfer the heat around your boat??

 

[David2452]

I@m pretty sure he means no exhaust duct, i.e. heater stub irect to deck mushroom, not the warm air duct.