Wallas 22dt Deisel heater

[Popeye2]

Wallas 22DT deisel heater . The on-off switch light flashes after 30 seconds and the fan stops. It shuts off soon after. No fuel gets pumped up from the tank one meter below. That new hose is dry. I just serviced it with their service kit they mailed to me from Uk. There is no dealer here in portugal. This unit worked fine untill i took it from my previous boat and tried to install it in my current boat. Would it help to try and fill that fuel hose with deisel first? It sounds like its struggling to pull up thr fuel. Anything else i can try. In order to avoid sending it to Uk?

[MartinR]

Yes, you should prime the hose unless the fuel pump is mounted very low. There is quite an art to installing these.

[coopec43]

Maybe something here?

https://www.scanmarineusa.com/wp-con...2013-Eng-s.pdf

https://www.youtube.com/watch?v=iv7LOa39rU8

Clive

[Popeye2]

Originally Posted by MartinR

Yes, you should prime the hose unless the fuel pump is mounted very low. There is quite an art to installing these.

Thanks. So i leave it soaking in the fuel tank?

[MartinR]

A new pump lifts about 2m. A used pump maybe a little less. 1m should normally be no problem, though. Just try to fill the pump with a little diesel for priming before connecting the hose. Also, it might need a few/many starts before the fuel supply is good enough to keep the flame sensor happy. Every air bubble basically stops the heater. It all depends on size, length and lift of your fuel line. Ideally the fuel line should have its own pickup in the tank. Can you Feel/hear the fuel pump running?

[coopec43]

Originally Posted by Popeye2

Thanks. So i leave it soaking in the fuel tank?

I don't know how the heater works but to prime a pump you fill the pump and inlet tube so the pump can pump the diesel. (a pump cannot pump air)
Maybe you should read the manual.


Clive

[Popeye2]

Originally Posted by MartinR

A new pump lifts about 2m. A used pump maybe a little less. 1m should normally be no problem, though. Just try to fill the pump with a little diesel for priming before connecting the hose. Also, it might need a few/many starts before the fuel supply is good enough to keep the flame sensor happy. Every air bubble basically stops the heater. It all depends on size, length and lift of your fuel line. Ideally the fuel line should have its own pickup in the tank. Can you Feel/hear the fuel pump running?

Thanks. Cant hear the pump working. When the heater was in the other boat the pump used to make a ticking sound. Now i just hear the fan seem to struggle and the turn off. On fan mode only, the fan works fine.

[MartinR]

Checking voltage to the pump is probably next step.

[MartinR]

Or maybe giving the fuel pump a little tap..... . Can get stuck when out of service for a while.

[Captain Puget]

You should hear clicking from the pump. However, before you take it in for service, carefully check all fuel line connections. even a small air leak will stop a Wallas from working (from personal experience).

[basssears]

Shouldn't gave to prime it, those are self priming. How many times have you tried? Manual says it can take multiple start attempts to fill the fuel line. Can you see fuel moving through the line? DT30 makes same ticking pump no use, if not hearing that could be wiring. Is this off main tank or day rank? Not being snarky, but you have fuel in there right (ask ne why I always ask this question)?

[Popeye2]

Originally Posted by basssears

Shouldn't gave to prime it, those are self priming. How many times have you tried? Manual says it can take multiple start attempts to fill the fuel line. Can you see fuel moving through the line? DT30 makes same ticking pump no use, if not hearing that could be wiring. Is this off main tank or day rank? Not being snarky, but you have fuel in there right (ask ne why I always ask this question)?

Tried one million times. No fuel in the line. A 10 litre (full) tank one meter below the heater. Yes i will check the wiring.

[psneeld]

Air leaking at the fuel line inlet to the pump. Use 2 wrenches and squeeze the daylights out of them to tighten that acorn fitting.

That was suggested by the dealer and worked for me several times when mine was new.

If the wrenchs move even a cm, it might do the trick.

Priming is a folly, either the pump is bad you have an air leak, or the fuel line requirements have been exceeded.

No ticking, either bad pump/brain board or wiring.

[Popeye2]

Originally Posted by psneeld

Air leaking at the fuel line inlet to the pump. Use 2 wrenches and squeeze the daylights out of them to tighten that acorn fitting.

That was suggested by the dealer and worked for me several times when mine was new.

If the wrenchs move even a cm, it might do the trick.

Thanks. Will try

[basssears]

The fact it only tries for 30 seconds seems odd to me. IRRC (which I may not, it's been a bit since I did this) it tried for quite a bit longer than that to prime itself before giving up when I started with a dry hose.


While you're checking the wiring (which is mostly just a harness, right?), perhaps also try disconnecting power completely, I had to do this once to kind of reset the system after it got a little discombobulated.


I don't have manual in front of me, are there fuses anywhere in the heater itself to check? Could be getting power to the blower and the control head but separate fuse is not allowing power to the pump?