Heater pops the circuit and wont stay on

[terkim99]

We have a 3807 that has 3 heaters and 3 air conditioners. Last weekend, we put the heat on (because we live in Michigan and it is still flippin cold!). We only put the heat on in the salon and after about 7 minutes, the breaker was tripped and the furnace was shut off (the switch moved from on to off). We tried just putting the front heater on and after a while the same thing happened. We then tried the a/c in the salon and the front and it was fine but the air temp was in the 50's. Does anyone have any idea why we are tripping the breaker with the furnace on?

[km1125]

A couple things first... Your sig shows a the boat is a 3607 but in your post you have 3807. Which one is correct? (not that it would matter much with this issue though... just confusing). Second... there is probably no "furnace". You likely have reverse-cycle air-conditioning, which provides heat. Some have a supplemental electric heating element and some do not.

Now, the actual issue. Was there water flowing when any of the three systems were running?? You need water flowing through the system to transfer the heat (or cold) to the lake. If the seacock wasn't opened yet, or the system not primed, then no seawater will be flowing and none of the units will provide heat or cold (well, they might work for a few minutes, but then shutdown).

Have you used the units before in either heat or cooling mode THIS YEAR yet, or was this the first time?

[terkim99]

Oops! We just switched (this winter) from a 3607 to a 3807, so the boat is new to us. We have the reverse cycling air unit, as you said (no furnace). I guess I am still trying to get used to sea terms vs. land. ha ha. The seacocks were open and water was running out of the exhaust when we were underway. I guess we did not really verify if there was water running when we were in the dock and the heat mode was on. We did use the a/c last week and if memory serves me right, we did use the heat mode a few weeks ago. My husband cleaned out the strainer but it still tripped the panel switch after he cleaned it (which was not that dirty). That's about all I know.

[km1125]

When you write " The seacocks were open and water was running out of the exhaust when we were underway."... it's a little confusing. Makes me think you are referring to the engine seacocks and water out the engine exhaust.

To be clear, I'm talking about the seacock for the HVAC and if water was coming out the exit ports for each HVAC unit. If the strainer he cleaned was for the HVAC, did he re-prime the system after to make sure water was flowing?

[bud37]

Like KM says, there needs to be water flow thru the system out the hull outlets for the heat / air.....verify water flow first before anything else.

[tomschauer]

As everyone mentioned you need water flow. Turn on just one of the units, the seawater pump should run, and you should have water coming out of three different outlets on the boat. If not, you may need to bleed the pump for just a second or two at the discharge. If you have good flow through all three outlets and your breakers are still tripping, you have a different problem,
Keep us posted.

[Viper]

On a 3807, if it's set up the same as mine and others I've seen, the main cabin and aft cabin AC discharges come out the same area as the engine exhaust right at the water line, not out the side of the hull. The forward birth AC discharges out the starboard side hull right above the water line.

The first thing I would check is the voltage on shore power line 2 and the condition of the power cord ends and the boat's inlet. If any area of the plug around the contact prongs is discolored or melted, the cord and or pedestal and inlet are suspect. Try using a different cord and pedestal and see if you get a different result.

[terkim99]

I am heading out to the boat tomorrow and will evaluate the water flow and electrical cord at the boat inlet.