Heater on first day out

[MRMoffat1]

Boat fully warmed up, Heater on high, the heat was reasonably warm when boat on plane/high rpms. When boat at idle, the heat was much, much cooler, approaching just blowing air.

I think I remember last year the heat as hot when on high at high rpms and at idle.

Would accidently swapping the two hosed into the heater explain this? The boat was winterized last oct, and the service dept did expell any water from the heater and reattach the hoses. Other explainations?

[jleger98]

I would think so. 1 hose is to bring hot water in, the other is to expel it. If they are reversed, the heater would be trying to bring it hot water from the "downstream" hose. When you are on plane, this might be ok because there is more water pressure in the system. At idle, there is less. I would definitely try switching them.

[dogbert]

I don't think it matters how the hoses are attached. I'd wonder if something got in there that's blocking it. Reversing the hoses could clear that up.

[chpthril]

I dont think the heater core is directional in a boat like some cars are. Are both hoses and nipples the same size?

I would look for a pinched/kinked hose on the feed side at the engine. Any kind of restriction would slow the flow of hot water at low RPM's.

[illiniboarder88]

can someone take a pic of where their heater hoses hook to the block?

[buffman]

I will try tonight if I get time for ya!

[MRMoffat1]

I dont think the heater core is directional in a boat like some cars are. Are both hoses and nipples the same size?

I would look for a pinched/kinked hose on the feed side at the engine. Any kind of restriction would slow the flow of hot water at low RPM's.

I reached back in there while out on the water. It seemed like both hoses were the same size.

[mtnsmith]

It sounds more like there is some sort of restriction of water flow some how, maybe something is kinking it so that the heater core only gets a lot of flow during higher rpms. On my heater there is no in or out necessarily.

[MRMoffat1]

Thanks all for the ideas. Will inspect closer next time I'm out, and report back - probably a week out if not two.

[scoot18]

I will try to get some pics for you later today. But in the mean time, one hose connects to a nipple on the forward part of the intake near the t/stat housing, and the other connects to an outlet from the water pump. As far as hose hook up, it doesn't matter which way you hook up the hoses, you could change it at either end and it would not change the performance.

I can tell you that on my heater, it does the very same thing, when at idle there is no heat. The engine has to be running at a higher rpm to have enough force to push the water through the core, because it is so far away from the engine. I think you may be chasing after a normal condition. The service tech at my dealer told me about this characteristic before we ever got our boat delivered. He wanted to let me know what to expect from it.

Just for a test, next time you are out and have the boat idling, push in the nuetral button and goose up the throttle to about 2500 or so and see if you get the heat.

I think you are OK.

[MRMoffat1]

I will try to get some pics for you later today. But in the mean time, one hose connects to a nipple on the forward part of the intake near the t/stat housing, and the other connects to an outlet from the water pump. As far as hose hook up, it doesn't matter which way you hook up the hoses, you could change it at either end and it would not change the performance.

I can tell you that on my heater, it does the very same thing, when at idle there is no heat. The engine has to be running at a higher rpm to have enough force to push the water through the core, because it is so far away from the engine. I think you may be chasing after a normal condition. The service tech at my dealer told me about this characteristic before we ever got our boat delivered. He wanted to let me know what to expect from it.

Just for a test, next time you are out and have the boat idling, push in the nuetral button and goose up the throttle to about 2500 or so and see if you get the heat.

I think you are OK.

I'm with ya, I will not rule out your thought. My recollection is it's different this year, than 2006 and 2007 spring, but how much did I pay attention in earlier years? I don't know.

Bottom line I must admit, if yours is doing the same thing, and its the exact same setup as mine, then it starts swinging in favor of "that's the way it is".

Good thought, will look at. Thanks.

[scoot18]

can someone take a pic of where their heater hoses hook to the block?

Thanks all for the ideas. Will inspect closer next time I'm out, and report back - probably a week out if not two.

OK, I meant to do this earlier this week, but you know how that goes. I took some pics this morning to help you gents out with your heater questions. Again it doesn't matter which way you hook the hoses up, just so long as the water moves thru the core, the blower motor is not particular to which way the water is flowing. See pics for details.

[MRMoffat1]

scoot18: Nice help with the photos! Boats been back in the garage for a week now. I am still going on the theory that something seems wrong otherwise I think I would have done this same tap dance/fire drill the past two seasons. Looks like I might be another week out on getting the boat back out - weather.

Another theory I'm going to look at I realized after thinking about it, is the potential coupling with the shower head install. The bildge pump started to automatically turn on about two miles from launch. I noticed the rear 22Ve compartment where the shower head is was filling up with water and draining into the bildge. I noticed the shower head on/off lever was on "on", and both hot and cold fixtures were turned to "full". The shower pump was never turned on (switch on dash = "off"). Once I turned everything off, no more water in bildge, bildge pump never went on the rest of the day. I'm wondering (1) enough force for water to exit the shower head without the pump turned on, and (2) was this all happening during the same time I noticed the heater not working, and (3) if so, does these have anything to do with each other. I don't think so, but I don't remember, so we might have a Laurel and Hardy situation here, and I need to go back out and look at each separately. I did not mention the shower head issue before because I had "fixed it".

[MRMoffat1]

Picture of shower head and location.

[MRMoffat1]

Down at my Tige Dealer's today saying my goodbyes. He was one of them that just couldn't get thru the down times this time. Had a chance to talk to the service dept which will be around until the liquidation sale is done, next 2-3 months. Here is what they say:

Heater should be hot at all times once engine at temp, whether at full RPM or idle.

They did not think water should be coming out of the shower head unless the pump switch turned on at the dash, even with the head lever turned on, and both cold and hot knobs turned to full. Due to the impeller in line with the pump, apparently.

Still planning to do some troubleshooting tests to verify all of this, and/or figure out what is happening.

Restriction in the line is starting to sound like the issue if I believe above.