Block Heater Location Issue

[sandspur1966]

Notwithstanding the obvious, why do this in the spring questions...

Had a local mechanic doing some odds and ends projects and it was something I was planning on getting to anyway so it was a "while he's in there" thing.

Anyway, I went to the boat and had some concerns and was hoping for the "collective perspective" here.

1) My first question is location... The elements are installed in the 3/4 plug slots in the circulator pumps themselves, not the block. I've had three other boats with heaters and this is the 1st time I've seen this. In addition the stbd one is making a surprisingly loud boiling sound indicating it doesn't have enough circulation through the pump I am guessing.

2) They are installed into residential (albeit outdoor) 120v GFCI 3 prong plugs when I asked for them to be wired into the panel on a GFCI breaker.

Thoughts? I'm about to call him and tell him what I want changed but I get the sense that the friend who recommended him feels I'm being too picky and while I don't mind being labeled picky, I was wondering where you guys are on the matter... Just for balance?

 

[MikeP]

I agree that they should be in the block as per the DD recommendations in the service manual. OTOH, if I had them in the location you describe and they seemed to be working fine, I wouldn't change the location.

Often, they are put in in other than the DD-recommended location because the alternator bracket does not allow enough clearance for the heaters available nowadays to fit in that block plug hole. The bracket can be modified to work just fine but it does require cutting a large diameter hole in the center of the mounting point. It's easier to NOT do that...

If you are needing to replace the heaters for whatever reason, another option is to go with oil-pan heaters. I prefer block heaters but many folks prefer the pan heaters...

My block heaters (1500W each and in the DD location) have always made a slight boiling sound, both the ones that were on the boat when I bought it (installed in 1980 when boat was new) and the new ones I installed a couple of years ago when one of the old ones quit. The first pair of heaters fit in the DD position with the stock alternator bracket but as stated above "modern style" block heaters will not fit without greatly enlarging the hole in the center mounting point of the bracket.

 

[workingonadream]

all of the block heaters I have seen have gone into the block with the exception of the auxiliary ones like I have on my boat. as for the power source, mine plug into a 110 outlet like the one you are describing. if it is not a gfi outlet, just remove the non gfi outlet and replace with a gfi one.. good luck

 

[MikeP]

Depending on the boat/year, it may have master GFI breakers at the main panels. IF that's the case, there is no need for an actual GFI outlet. You could just add a new circuit breaker for that purpose and wire the block heaters into that breaker/with switches wherever you want them. The "failure" on the old block heater of mine was when it started tripping the master panel GFI a ew minutes after it was turned on.

Some folks install thermostats to control the block heaters as well. Our boat had those when we bought it but I removed them since I never use the block heaters that way - to maintain a temperature for extended periods. I only use them specifically to start the engines when they haven't been run in a while. So I turn them on a couple of hours prior to the expected startup. The water temp gets to around 120-130F by "start" time and the engine block is quite warm to the touch.

 

[racclarkson@gmail.com]

Mike P is right on. Mine are 1000 watts and heat to 105 in SC winter or 125 this time of year. Adding heat a few hours prior to starting insures instant start and reduced smoke. Mine are located in the plug located in the piping going to the oil cooler and are plug-ins. Yes, they make a boiling noise, but there's no way they'll ever be close to not being underwater. In the winter, the ER is a very comfortable space will all that gentle radiant heat.

 

[sandspur1966]

Thanks guys, so nobody sees anything intrinsically wrong with them being installed in the circulator pump?

I tend to like to keep to manufacturer spec when possible but don't need to be dogmatic about it...

plugs in my ER is a pet peeve though so I'm going to push on that... in particular because I was very clear about it on the front end.