Heater Cuts Out by Itself

[davis911s]

Hi everyone. I have a "Mikuni My16" installed. This is in my VW bus (Not a boat) but you guys here are awesome and seem to know lots about these heaters.

The problem is that it turns off by itself. It will go through the normal start up procedure, but it will turn itself off after only 1 or 2 minutes of operation. The air does not get "hot" , slightly warm maybe. It is -15 degrees celcius here so It is definetly NOT overheating. I am installing this in my non - heated garage

The heater is only dry fitted for now, the exhaust and intake are routed out of the bus through the floor (I am not a big fan of carbon monoxide). The control box is mounted vertically on the back of a flat bench.

The fuel pump is not yet mounted since I am not 100% sure where I will be installing my aux fuel tank. But I can't see how the pump not being mounted could cause this.

ANY IDEAS? I would love to have good heat with this cold weather.

Thanks everybody

Shawn
Living in the middle of the dry Canadian Praries

[cal40john]

I'm not familiar with your brand, but mine has diagnostic codes to tell you why it didn't start. Did a quick search on the web and found this:

Mikuni Heating

Are you getting a flashing light to tell you what's wrong? They also talk about no fuel. If I've had my whole system apart and try to start the system with empty fuel lines, it takes 3 start ups and auto shut downs due to no fuel before it has cleared the lines of air.

John

[senormechanico]

John beat me to it. If this is a new install, that's probably all it is.

Steve B.

[davis911s]

You guys were 100% right. It was air in the fuel lines.

You guys are extremely helpful THANK YOU! You make me want to go out and buy a boat haha

Thanks again

Shawn

[cchesley]

Okay, I've got a bit tougher challenge. My heater (Hurricane by ITR) runs great for 2-3 hours when cold. Once up to temp it starts to cut out (Flame out indicator) every 10-20 minutes. Usually restarts within one or two tries or after reset.

Flame Out is usually an indicator of air in the line. However, Why no flame out for first 3 hours????

[cal40john]

Originally Posted by cchesley

Okay, I've got a bit tougher challenge. My heater (Hurricane by ITR) runs great for 2-3 hours when cold. Once up to temp it starts to cut out (Flame out indicator) every 10-20 minutes. Usually restarts within one or two tries or after reset.

Flame Out is usually an indicator of air in the line. However, Why no flame out for first 3 hours????

Once again knowledge I have is not of your make, I'm assuming generically most functions are the same.

Could be a lot of things. Most of which I don't have the answer to.

One: Do you hear the clicking of the fuel pump, or has the pump stopped? On my friends boat with a 20 year old heater we had two things go wrong related to the pump turning off. One was the relay that supplied power to the pump needed to be replaced, every once in awhile it would stop supplying power to the pump.

The other problem with a stopped pump we had was the overtemp switch. There is a switch screwed to the outside of the heater. It is in the power line to the pump. If the heater gets too hot the switch breaks power to the pump leaving the logic circuits to do a controlled shutdown. In our case the switch had corrosion in it and needed to be replaced. If your heater is actually getting too hot, then could be a lot of things, guesses could be obstructed inlet/outlets, fan running too slow, improper fuel rate....

Two: If the fuel pump is running, is the vent clogged on the fuel tank? Maybe it takes awhile to put enough vacuum on the tank to shut it down. Try opening the fill when the heater stops.


John

[cchesley]

John, thanks for your reply.

I've started with the last (easy) option first. I vented the fuel tank fill cap. If it now runs for several hours, then I'd say that this is the issue.

I'd need to do more investigating to differentiate between high temp cut out on the fuel pump vs the aquastat cut off which seems to be working and is based on coolant temps.

The fuel pump doesn't seem to be hardly even warm so perhaps it is just a bad switch to the fuel pump. I had run the unit without the side panel on in case it was something like this but still had the issue and the pump was barely warm to the touch.

Maybe it is just a bad switch though.

[AQuery]

I'm having the same or at least similar problem with my Hurricane II heater. After operation of approx. 1 or more hours it will begin flaming out on every or most cycles. After it's been off for a while, it will restart but again die after approx. an hour of operation.

What finally resolved your problem? Any help is greatly appreciated.

[MarkTilley]

We installed a narrow hood over our Hurricane exhaust to keep out precipitation. Wrong thing to do!

The exhaust recirculated under the hood and got sucked back into the intake, resulting in a flameout due to insufficient oxygen. Removed, the hood, problem solved. (It actually took a lot of troubleshooting by the dealer to figure that one out, as they hadn't expected the hood to be a problem at all.)

What made it the troubleshooting trickier is that the first weekend we were on the boat it ran flawlessly. But we realized later that that was a really windy weekend, so the exhaust got blown away without being sucked back in.

We're just finishing our first winter with it (just outside Toronto) and I have to say we're more than pleased with how it's performed.

Mark Tilley
s/v Saving Grace
Saga 43 - 40

(Yes, I realize this is an old thread - but it had an unanswered question.)