Diesel Heater Advice

[DefinitelyMe]

Originally Posted by goboatingnow

You may find that heater proves difficult to start

Why is that?

[jtsailjt]

Originally Posted by DefinitelyMe

Why is that?

A longer exhaust hose length introduces more friction that slows the flow of gasses out the exhaust pipe and that means the inflow of oxygen to be burned will also be slowed. The manufacturers recommendation can probably be stretched a bit but I have no idea how much before the heaters ability to start and run reliably will be affected. I don't think anyone can give you an exact length though.

[mako]

No matter what, I think it prudent to have multiple detectors (CO, CO2, smoke, propane).

Domestic units are cheap. Batteries go dead.

My boat was saved from an electrical fire that I caught within a minute in the middle of the night. Saved by a $10 Home Depot detector with a fresh battery I had recently replaced.

[Bill O]

Originally Posted by DefinitelyMe

Thanks, but actually I'm pretty sure this is one instance when the manufacturers installation instructions should definitely NOT be followed! Most of the instructions are either unintelligible or irrelevant, and the rest are either unachievable, absurd or just wrong based on the wealth of knowledge I've gained from this thread and the YouTube series posted above.

As for the combustion intake, my take-away impression has been that it probably doesn't make much difference where you get it from. There are pros and cons to every option. I'm going to leave mine open, in part to try to compensate for a long (2m) exhaust with nearly twice the recommended compound bend angles in it.

If the instructions that came w/the heater you purchased were not that good, would read/follow the Espar instructions that you can find online. They are easy to follow and are consistent w/the Aussie guy's video instructions (which were also very good).
Unfortunately they don't provide any exhaust tube size recommendations (increase) if you had more than the 270 degree bends or longer than 2m for the exhaust run. Would go the next size up but then you will need adapters from the original 24mm exhaust port.

As already described the increased bends and longer run will result in increased back pressure and incomplete exhaust removal. This will then carbon up the chamber quicker make it more difficult to start.
Good news is you purchased the 2kw model, so possibly you will be running it on high most of the time and will help burn off excessive carbon. This should help reduce maintenance of the unit.

[jtsailjt]

Originally Posted by Bill O

Good news is you purchased the 2kw model, so possibly you will be running it on high most of the time and will help burn off excessive carbon. This should help reduce maintenance of the unit.

I think this is wise advice and worth re-emphasizing. Running a small diesel heater on high rather than a big heater on low will lead to much fewer problems. I pondered that when I installed the Webasto heater on my boat but it turned out that the space where I wanted to install it wouldn't permit a bigger one anyway so the decision was an easy one. Using the smaller heater it takes more time to get the boat up to temp but it does get there, and once temp reaches about 70, it cycles on and off to keep it comfortable and you can barely hear it running. If it's really cold and I want heat fast, I start the generator and turn on the 2 reverse cycle air conditioners or an electric foot heater to help the diesel heater initially raise the temperature and then the diesel heater can easily take over so I can shut off the generator after a relatively short time.

[DefinitelyMe]

I'll try it with my current plan, which includes about 450 degrees of bends in the exhaust. I have not yet read the espar/webasto/eberspacher installation manuals but the knock-off that I have says max 270 degrees in each, inlet and exhaust. Since it's a closed combustion chamber / closed loop system it stands to reason that by omitting the inlet ducting completely I should gain a bit of leeway to bend (har har!) the rules a bit on the exhaust.

Heater, fuel system and wiring went in today. Bad news is I need to order more parts for the ducting, and with Christmas looming the shipping agents are all overrun here. I doubt I'll get it before January.

Tried looking for alternatives locally. Thin-wall (flexible) copper tubing should work I'd have thought. Same stuff they use in air con installations and water heating. Might even be better since the bore is smooth (so less internal resistance to gas flow). However the only local supplier who stocks that size will only sell it in 50' rolls. We'll see how desperate my wife gets!

[newhaul]

Originally Posted by DefinitelyMe

I'll try it with my current plan, which includes about 450 degrees of bends in the exhaust. I have not yet read the espar/webasto/eberspacher installation manuals but the knock-off that I have says max 270 degrees in each, inlet and exhaust. Since it's a closed combustion chamber / closed loop system it stands to reason that by omitting the inlet ducting completely I should gain a bit of leeway to bend (har har!) the rules a bit on the exhaust.

Heater, fuel system and wiring went in today. Bad news is I need to order more parts for the ducting, and with Christmas looming the shipping agents are all overrun here. I doubt I'll get it before January.

Tried looking for alternatives locally. Thin-wall (flexible) copper tubing should work I'd have thought. Same stuff they use in air con installations and water heating. Might even be better since the bore is smooth (so less internal resistance to gas flow). However the only local supplier who stocks that size will only sell it in 50' rolls. We'll see how desperate my wife gets!

Check with a few of the local plumbers they may just have a few scraps laying around they are willing to make you a deal on

[flightlead404]

Be careful using insulating wrap on the exhaust. It can hide cracks in bed welds and cause high heat to exacerbate weld and corrosion issues. Further it can accelerate corrosion. Make sure if you use it to check underneath annually.

[pcmm]

Originally Posted by DefinitelyMe

Well there goes my morning tomorrow!

Heater bought. Following the advice to go smaller I decided to get this one (a 2Kw model). Yes I will also get a CO detector (hopefully available locally) and will get some more insulation tape for the hot air outlet hose. It might be quite a long run; perhaps as much as 15 feet so definitely worth it if it's thin-wall metal pipe.

Thanks again everyone. Some really great advice here.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

If your heater has 75mm (3in) ducts, you got shipped a 5kw model labelled as a 2kw ( this is common). Actual real 2kw models of these heaters are hard to find.

For installing on a boat, you really need to bin all the parts that come with these heaters except the heater, wiring harness, controller pump and fuel hose. All the clips, exhaust etc are very poor quality. I've installed one of these on my boat and have been happy with it but It needed close to $400 of parts to get it installed properly:

The muffler that comes with these things are garbage and dangerous on a boat as they are not sealed at all.

you'll need:
a transom exhaust fitting ($50)
exhaust elbow with drip loop ($75)
proper espar type exhaust hose ($100)
proper muffler (if you want one) ($80)
real stainless exhaust clamps
exhaust wrap
a better filter ( the included ones crack very very easily)
depending on the install a different install bracket

CO detector is a must.

[Pete7]

Originally Posted by DefinitelyMe

They really aren't very generous with the hoses included in the kit. I think the only thing available locally is going to be copper piping. But will the extreme temperature changes experienced by the exhaust hose crack the soldered connections? I'd really rather not have a load of connections at all if they can be avoided. I've never worked with copper piping before either. Can it be bent fairly easily rather than making connections? The stuff used in refrigeration can be but this will be more like 1 1/2" diameter. Tricky........

Please don't solder copper pipe as exhaust hose:


https://www.bbc.co.uk/news/uk-englan...n%20Windermere.

[Atcowboy]

Originally Posted by Windpilot

I kept it simple. Just use the right high quality exhaust fitting and upgrade the muffler supplied by China. Make sure exhaust has no leaks, I ran it downhill so no water trap needed.5kw , 2 vents blowing in aft cabin only on 41' Hunter will definatly heat the boat.

Where is that exhaust fitting located on the boat? Looks like it might be on some part of the cockpit combing/molding (vs. the hull)?

I'm very interested in installing a heater on my boat, but I'm equally worried about the skin fittings getting stuffed by waves...

-AT

[newhaul]

Originally Posted by Atcowboy

Where is that exhaust fitting located on the boat? Looks like it might be on some part of the cockpit combing/molding (vs. the hull)?

I'm very interested in installing a heater on my boat, but I'm equally worried about the skin fittings getting stuffed by waves...

-AT

Mounted high in the transom on my sailboat
The stainless part in the picture.

[Windpilot]

Originally Posted by Atcowboy

Where is that exhaust fitting located on the boat? Looks like it might be on some part of the cockpit combing/molding (vs. the hull)?

I'm very interested in installing a heater on my boat, but I'm equally worried about the skin fittings getting stuffed by waves...

-AT

I don't have a photo handy. It actually comes out through my stern cockpit locker. I guess it's about 2' above the water line as well as about 1 foot onboard. It has a smooth "s"curve after the fitting before the long muffler which runs uphill and further inboard and up.
I have never had water even close to the exhaust in ocean seaways and I have no concern of a breaking sea or splash causing any concern at all regarding that exhaust at least.
I will never ever have a water trap issue and consider the position slightly safer as far as exhaust gases are concerned.
And I do so love the heater these days!

[DefinitelyMe]

Originally Posted by newhaul

Mounted high in the transom on my sailboat
The stainless part in the picture.

Yes that's where mine will go too. About 4" below the top of the transom. The exhaust hose will come down to the fitting, thus it should be pretty tough for water to get in there in any great quantity. We've only once, in 2007, had conditions bad enough that we've taken significant water in over the stern and I could always stick a bung in it.

Unfortunately the package containing the exhaust hose, transom fitting and drainage loop has been lost by the courier. For now I have modified a piece of copper pipe to work. Once the proper install is complete, whenever that might be, I'll post a couple of pictures.

I feel like I've learned a huge amount from this thread. Thanks to everyone who has contributed.

[jtsailjt]

For extending the season here in Maine a diesel heater is close to a requirement so I’ve installed and used 2 on my last 2 boats. In my aft cockpit boat I installed the heater near the transom and the exhaust was high up on the reverse transom. In 11 years I never had a problem with water getting in. Then, 5 years ago I got a center cockpit boat and mounting the heater near the transom would have meant about a foot from my head and a very long run to get heat up in the forward cabin. So I found another location just aft of amidships and mounted it there with the exhaust exiting 6” below the sheer line and have had no problems with it at all. When installing these exhaust lines starting from the skin fitting the line runs slightly up so when the boat is level water will run out. But on a midships installation like mine you also fun it onboard just beneath deck level for about 2’ so even if you bury the rail on that side the water won’t get to the heater and will run back out. On the other tack spray could get in but with the boat heeled the exhaust fitting is high above the waterline. As has been mentioned earlier if conditions are really terrible there’s a plug you can use to temporarily close it off. Or just use a wooden plug., but I’ve never run into conditions where I had a problem with it with either my transom or mid ships location.