ESPAR DIESEL FORCED AIR HEATER

[Tantramar]

I have an Espar diesel forced air heater on my boat. I don't use it a lot but this year when I tested it - no go. I diagnosed the problem as a faulty fuel pump. The power to the pump was good but no pumping. I bought a new fuel pump. Still no pumping. I bought another fuel pump. Again, no pumping. I tested the fuel pump(s) and they seem to make one click and deliver a bit of a squirt then nothing. By disconnecting the power and re-connecting the power supply the pump sort of works. It appears that every time there is a pulse of current the pump clicks and delivers.
Is this normal and is there something on the control board that delivers a pulse of current instead of just being "on"? There is always current at the connection point with the fuel pump.
Is it possible that I have yet another faulty fuel pump?
Hope someone can offer a solution.
Thanks.

[Windpilot]

They just pulse, I have a Chinese knock off for the last 4 years and did my own investigation as to how they work. They're pretty much the same.
But, the pulse pumps should start and keep going, slow at startup, faster at fully on max.

[PippaB]

The pump expects a voltage pulse to drive the coil. If you make/break your test connection you should get a pulse every time you make the connection. The faster you pulse the higher the flow.

If the controller is providing a steady 12V to the pump then the problem is in the controller.

[deblen]

May help : https://dksi.com/wp-content/uploads/...B9Z473sakE6iZW

[deblen]

I hate to suggest an asian knock-off,but....

https://www.youtube.com/watch?v=HEBRWPYZlm4

[senormechanico]

Pippa B has it exactly right.
The pump needs pulsing 12 volts to work.
You didn't mention the model number, but if it's like the one I had on my previous boat (D3 as I remember) the controller may just have a stuck relay. I think the relays just plug in and probably aren't expensive.

[Tantramar]

Many thanks for the knowledgeable replies. I am now sure that the fuel pump requires a pulse to operate. I will have a look at the control board and associated relays but unfortunately the unit is probably toast as parts are unlikely to be available.

[senormechanico]

If the relays are "plug in" and likely are, it shouldn't be too hard to track them down.
You still haven't mentioned the model number of your heater.
Check out ebay. There are lots of heaters and parts listed there.
One example:


https://www.ebay.com/itm/16649212887...Bk9SR-7gvJuqZA

[Pizzazz]

The diesel heaters are pretty basic and the Chinese knock-offs are just as good as the original Espar/Webasto units. They do have parts that break down, sometimes often, such as the glow plugs, the pumps, the filters and the control boards. These parts cost very little and it is easy to replace and carry spares. The biggest cost is the ducting and you already have this.

Given how cheap the whole units are, my advice is just replace the whole unit with a Chinese knock-off for $200, carry two glow plugs and two pumps as spares and be done with it.

[PippaB]

Pretty much all of the Chinese heater are knockoffs of the Espar, and they all seem to be compatible with the many Chinese heater control panels. I have not tried it, but would think the odds are pretty good that the knockoff controllers would work with the genuine Espar heater. Not a huge investment to find out.

I have this one (on a knockoff heater), it does the job. If you leave the electricity on to it all the time the screen will fade and not last much more than 6 months or so, otherwise it seems OK.

Go to your favorite online seller and search "parking heater controller", there are lots of options, some more basic than others, some that specify they work with the genuine deal. Check the shape of the connector in the photos, the knockoffs generally use a triangular 3-pin connector, the Espar may use a square connector, both styles available for < $25.