Airtronic heater issues

[blinkerfluid]

I'm working through projects on our new-to-us boat, and at the moment I'm trying to figure out our heater issue (Espar Airtronic D4).

When we first bought the boat, the heater wouldn't ignite at all, which turned out to be a loose hose clamp that was allowing the system to lose prime. We got that fixed, and now the heater starts up on it's first try, however it'll only run for about 10 minutes then shuts down and doesn't try to restart. I read a trouble shooting guide from espar of Michigan which pretty closely describes the problem we're having. Their suggestion is to replace the mini controller for the unit, but before I do that I thought I'd ask if anyone else has experienced the same problem but had a different solution.

As a side note, the unit clicks continuously (slowly at first and then increasing pace) during start up. I've not had an Airtronic before so was just wondering if this is normal?

Thanks

[goboatingnow]

Originally Posted by blinkerfluid

I'm working through projects on our new-to-us boat, and at the moment I'm trying to figure out our heater issue (Espar Airtronic D4).

When we first bought the boat, the heater wouldn't ignite at all, which turned out to be a loose hose clamp that was allowing the system to lose prime. We got that fixed, and now the heater starts up on it's first try, however it'll only run for about 10 minutes then shuts down and doesn't try to restart. I read a trouble shooting guide from espar of Michigan which pretty closely describes the problem we're having. Their suggestion is to replace the mini controller for the unit, but before I do that I thought I'd ask if anyone else has experienced the same problem but had a different solution.

As a side note, the unit clicks continuously (slowly at first and then increasing pace) during start up. I've not had an Airtronic before so was just wondering if this is normal?

Thanks

Clicking is normal, its from the electric fuel pump.

When you listen to it inside the boat, does it run roughly , i.e. like the flame isn't steady, you should have a good steady roar. Also are you getting significant heat for that 10 minutes.

The main things that shut these units down are

(a) flame failure detection ( or its sensor), i.e. a steady consistent flame does not get established

(b) low voltage

(c) air in fuel line

(d) blockage of the pump filter


(d) is a real gotcha, There is a little filter, inside the electric pump. Its accessed by removing the big aluminium nut in the pump. ( be careful you can wring it). the filter easily blocks and varnishes up.

You may also have another more obvious in line filter as well.


The electronics are generally very reliable and should be the last thing to be suspected.


dave

[blinkerfluid]

Yes, it lights off and has a nice steady roar, and I measured the air temp coming out at about 110F/43C. There may be a very light bit of black smoke at the initial ignition, but none once it's running.

It sounds like the unit goes into the boost mode for maybe 5 minutes, then gets much quieter for about 5 minutes before shutting off. I believe it still has a flame during the quieter time as it's still blowing warm air in the cabin and hot air out the exhaust.

Our boat has a large(ish) fuel filter just before the pump. So, while I haven't checked, I don't think the fuel pump is blocked. I know there was air in the lines, so maybe there's still a bubble somewhere that's causing problems?

I also know our fuel pump isn't oriented properly (perfectly horizontal), so I need to fix that, but the previous owner said the heater was working fine when they were using it over the winter of '12/'13. After that the boat sat with very little use for about a year and a half before we bought it.

[hpeer]

Just to second the clicking sound is normal.

Does it restart immediately after shutting down?

Ours has a kind of wire mesh under the glow plug that can get dirty.

You may want to try that. To remove the glow plug you need a special socket, which you can make yourself. The wires get in the way, so you need to deeply grove the side of the ratchet to let them pass.

Another real Hail Mary may be to try running it on kerosene. I know one guy who uses only kero, and others who run a few gallons few each season. Supposedly helps clean out some stuff. I do it simply because it is pretty easy, I carry kero for cooking so its onboard.

[witzgall]

The fuel pump is designed to be mounted at a 30 angle upwards. If the clicking is a sharp clicking sound, there may still be air in the system. When properly running, the pump should sound like a dull click.


Sent from my iPhone using Cruisers Sailing Forum

[blinkerfluid]

The clicking I hear seems to be coming from the heater unit itself, not the fuel pump. It is a fairly sharp clicking though, what else can be clicking besides the pump?

Once it shuts down, it never tries to restart. If it's not detecting a flame or has a low fuel supply will it try to restart?

[blinkerfluid]

Ok, upon further investigation, we found out that we definitely have a lot of air bubbles in the fuel line. We've tightened all the hose clamps (several were loose), but we're still having trouble getting all the bubbles out.

After looking at our system more closely we found out that we actually have 2 fuel pumps and an external regulator between them. Has anyone ever seen an install like this before? Our setup right now goes from the fuel tank, through a large fuel filter, into what I'm guessing is supposed to be a lift pump (much larger than the Espar metering pump), then to the external regulator (looks like a 2" diameter metal disc about 1/2" thick), then to the Espar metering pump and finally to the heater.

The metering pump is maybe 10" above the top of the fuel tank and ~3' away from it. I couldn't find where espar gives any specs for lift capacity of the metering pump and, other than saying it shouldn't be gravity fed, couldn't find any specs about where it should be located in relation to the fuel tank.

Unless someone can give me a good reason not to, tomorrow we're going to put new fuel line in and bypass the extra fuel pump and regulator. Hopefully this simplifies bleeding the system for us.

[hpeer]

It sounds like you have a Walbro low pressure fuel pump followed by a (Holly?) pressure regulator which is feeding y metering pump.

The metering pump can provide only so much suction. If you have a deep fuel tank then at low levels you will not be able to supply fuel to the heater through the metering pump.

Kinda think od it as a lift pump for the heater.

How deep is your fuel tank? I can't recall the specs right now, you may or may not need this optional pump.

I used this same set up before installing a day tank. I since removed it.

[blinkerfluid]

I'd have to measure to be sure, but I'm guessing the tank is around 14-16" deep. The metering pump is probably 8-10" above the tank. I figured there would be a limit to how high the pump could be over the tank, but haven't been able to find the spec.

[hpeer]

I can't recall, but it's more than that.

Doesn't mean someone didn't overthink it at time of origioinal install.

Done that myself, too often.

[hpeer]

I see two specs. 0.5 meter and 2 meter. Can't figure out the difference.

[blinkerfluid]

Yea I was able to find the specs in the heater manual finally. Has to be less than 30" from the bottom of the tank to the bottom of the fuel pump and less than 6'6" horizontal distance. Pretty confident that we meet both those requirements. Thanks for the help

[blinkerfluid]

I was able to re-do the fuel system for the heater and finally get all the air bubbles out of the line, but the heater still isn't working.

It starts fine on the first attempt with little if any smoke, runs for a few minutes and then shuts down, never tries to start a 2nd time.

Of course now I think I have other problems. That last 2 times I tried to start it, it failed both times. The first time the unit made this awful whining sound, followed by the fan running for a couple minutes but the fuel pump never started. The 2nd time it made the same awful whining sound, but the fan never even started. I don't know what the shining sound is, it's hard to describe. Sort of like the sound a high pressure fluid makes when it squeaks past a seal.. Of course there are no high pressure fluids on these units, but that's still the best way I can describe the sound.

We ended up pulling the unit off the boat, and I guess we're just going to have someone run diagnostics on it for us.

[Sandero]

Sounds to me like the controller is defective... You don't want bubbles in the fuel line! The pump clicking rate changes once the unit is running ... clicking fast at first.

If it's shutting down, the controller is sensing an out of spec condition or... it the controller could whacked. I had an Airtronic 4 and had to ultimately replace the control board (ouch$$) but that did the trick and now I have a second pump for spare after thinking the pumped was whacked. It wasn't.

[goboatingnow]

Faulty flame failure device.