Idle Heater Mod

[Brett B]

Great thread! I will probably install one of the CM30 pumps on my boat this year as well since I have the Monsoon and don’t get any heat at idle.

Looks like the CM30 is a centrifugal pump, therefore it will allow some water to pass through when it’s not running.

http://www.spx.com/en/johnson-pump-marine/pd-mp-marine-circulation-pumps-cm10-cm30-cm90/

I will probably wire a relay so this pump only turns on when I turn the heater on. I agree with Fman that I would rather not have it on the fuel pump circuit in case of problems, and I just don’t want the pump running all the time when it’s not needed.

Edited April 3, 2014 by Brett B

[SmoothWaterMan]

shawn is correct, the new gen motors (6.0/6.2/6.3) need to have it.

That said, the magnetic motor service life is over 5,000 hours. Well past your boat's expected use.

The circ pump doesn't run off the fuel pump. The fuel pump switching on is simply a trigger. This triggers the relay to start the circulating pump. You can trigger it with any source, but the fuel pump is an obvious one since you need water flow and fuel for the engine to stay running, and a very reliable source.

Malibu offers a pump kit, which includes the wiring harness and relay. Plug and play for $300. One can make their own, but I think this is a well thought out and easy installation.

Peter

Edited April 3, 2014 by SmoothWaterMan

[Fman]

Good news, bakes just dropped there price to $175 on the pump with free shipping!

What about running the pump off the high setting on the fuse buss? I would guess I would need to bump up the fuse from 5 amp 10 amp, but I cant see why this would not work? any thoughts?

Edit: another question, are you installing on the return line or feeding line from engine block? does it matter either way?

Edited April 3, 2014 by Fman

[jgates237]

I'm on this train as well. With the winter we've been having it's hard to believe we'll ever get any days that don't require an efficient heater.

I just saw the Bake's price, seems like a pretty good deal!

Edited April 4, 2014 by jgates237

[Fman]

shawn is correct, the new gen motors (6.0/6.2/6.3) need to have it.

That said, the magnetic motor service life is over 5,000 hours. Well past your boat's expected use.

The circ pump doesn't run off the fuel pump. The fuel pump switching on is simply a trigger. This triggers the relay to start the circulating pump. You can trigger it with any source, but the fuel pump is an obvious one since you need water flow and fuel for the engine to stay running, and a very reliable source.

Malibu offers a pump kit, which includes the wiring harness and relay. Plug and play for $300. One can make their own, but I think this is a well thought out and easy installation.

Peter

Peter,

I tried to send you a PM but it is not working... Do you have a part number for the wiring harness? price? I purchased the CM30 pump from Bakes but I am interested in the wiring harness.

Thank you...

[Brett B]

Good news, bakes just dropped there price to $175 on the pump with free shipping!

What about running the pump off the high setting on the fuse buss? I would guess I would need to bump up the fuse from 5 amp 10 amp, but I cant see why this would not work? any thoughts?

Edit: another question, are you installing on the return line or feeding line from engine block? does it matter either way?

Nice, I just ordered it from Bakes too. They must have seen us all looking at it and decided to move some inventory!

[05hammerhead]

Dang. I should have ordered from Bakes!

[Happy to ride]

I put in a pump years ago when I put in the extra heater core, (6 outlets now) and love it. Growing up as a plumber the water line pluming was a snap. I used a pump like "Heater Craft" sells but I bought it on line. The problem is that it has a rubber impeller like the one on the motor's raw water pump and will not let water through unless it is running. I didn't want the pump to run all the time, (it is not needed when up to RPMs), so I put a spring loaded check valve in as a by-pass when the pump is off. Then I put a "thermal disk", like a home furnace uses for the blower motor, in one of the heater core boxes. Now when the water is hot at RPMs the pump shuts off and when the core temp drops below 140 deg. the pump turns on by it's self. I wired the pump to a extra port in the power box under the dash and then programed the "AUX" switch on the "MUX" (info is in your owners manual on how to do this) so I can turn the pump on anytime I want, but do to the "thermal disk switch" it only comes on if needed to do a "pre warm" or when the RPMs are to low to move good hot water to the cores. I did put it behind the kick plate by my feet and I can't hear it run at all. When I winterize my boat I do run it when I drain the heater cores and pump antifreeze in so as not to lose the pump or cores if any water were to remain. We hit the water at around 48 to 50 deg. And the family loves the warm air. Just my two cents.

[SmoothWaterMan]

I believe the harness is about $75 with connectors and relay.

Peter

[ajive]

So this thread took a turn to a much more complex solution, but I'll at least report back that the y-fitting worked really well. There is still an obvious bump up in temperature when I take off, but now it goes from warm to hot instead of cold to hot.

[jgates237]

Good news, bakes just dropped there price to $175 on the pump with free shipping!

What about running the pump off the high setting on the fuse buss? I would guess I would need to bump up the fuse from 5 amp 10 amp, but I cant see why this would not work? any thoughts?

Edit: another question, are you installing on the return line or feeding line from engine block? does it matter either way?

Fman,

I've settled on where I'm going to put my heater and pump but still need to figure out the wiring. I recall you installing your pump behind the kick plate whereas I'm going to install mine in the bilge. Regardless, you have any recommendations how to wire this. I'd like to have the pump on at all times when the heater is but I'm not sure how to go about this or what to tap into. I like Peter's recommendation but I'm not sure how to go about it. I've been pestering the crap out of him but he's understandably really busy this time of year and is unable to assist at this time.

Did you install your pump on the return line? I think that's the way I've seen most installs.

Thanks,

[Fman]

If you are not going to have it come on with heater you need to tap into a source that is constant hot when ignition is engaged. I would use a relay switch, I used the seat heater fuse buss next to drivers seat for my constant hot. My pump comes on when heater is turned on high or low setting (orange wire off heater bundle). I'm not sure why you would always need it running when not using heater but it should be fine either way. The relay I purchased was a 40amp I picked up automotive store, it will have a diagram on it where the wires need to come from, pretty simple.

My pump is installed in the feeder line to the heater core.

We had dinner on the boat after riding on Monday and I left the heater running to test it, I still had hot air blowing after sitting for 10 minutes. It really does work very good.

[Fffrank]

Used my heater for the first time this weekend and it didn't provide any heat at idle.  Makes sense that an electric pump would help -- those that have added one do you ALSO need the Y pipe?

[shawndoggy]

7 minutes ago, Fffrank said:

Used my heater for the first time this weekend and it didn't provide any heat at idle.  Makes sense that an electric pump would help -- those that have added one do you ALSO need the Y pipe?

no, it's either or.

[ahopkins22LSV]

34 minutes ago, Fffrank said:

Used my heater for the first time this weekend and it didn't provide any heat at idle.  Makes sense that an electric pump would help -- those that have added one do you ALSO need the Y pipe?

 

23 minutes ago, shawndoggy said:

no, it's either or.

Agreed. I just have the Y pipe and my heat is HOT at idle. I have been in boats with the circulation pump and those work just as well too. A lot easier and cheaper to add the Y pipe. Granted the water doesn't travel as far in my boat as it would in your 23 LSV. Assuming the heater core is still under the dash.

[JulioEstevez]

Does someone have a link to the explanations about where to install the Y fitting? It looks like a simple fail safe upgrade

Thanks!

[CedarLakeSkier]

3 hours ago, JulioEstevez said:

Does someone have a link to the explanations about where to install the Y fitting? It looks like a simple fail safe upgrade

Thanks!

 

You can see the "Y" pipe in the picture below between the fresh water intake and the impeller.  The heater return is in the small part of the "Y" so the water is sucked through the heater at idle

 

[hunter77ah]

Does anyone know how to properly tap into the fuel pump to start the heater pump?  I've been poking around but can't seem to figure out how to get the fuel pump to trigger my relay for the heater pump.

[coldwater-echelon]

Can I ask why bother with this? Why not just switch the heater pump from the dash? This way you will have heat when the motor is not running as well.

[hunter77ah]

I have the l96. 

[granddaddy55]

On 3/10/2023 at 1:42 PM, hunter77ah said:

I have the l96. 

are you doing the pump like m5/6 that is on motor?  i installed the heatercraft aux pump switched off the dash accessory screen heater button colocated with core on the core’s return line by the dash.  it works great snd as mentioned heat with motor off snd key off since my boat has an accessory switch timer. my motor is a pcm crusader 6.0 liter.  and no i didnt install a bypass around the pump for when  its off  and i'm having zero issues.  i think you were worried about this in a prev post

are you married to this design?  your using i think the to heater line instead of the return.  i know malibu does it that way but is that really as good?  i heard some m5/6 heater setups aren't so good as far as heat output.  also  my install method,  if in a new heater core install,  allows heater switch to fill whole coolant system without turning on the motor.  you just top off the reservoir as it burps.    easy peazy!

 

Edited March 22, 2023 by granddaddy55