Cabin Heat on a 41AC

Jan 3, 2010
9
Hunter 41AC LA
I want to put some cabin heat into my 41AC. I am baed in Point Roberts in the Pacific Northwest and adding some heat in the cabin will extend my boating season. I am looking at a Webasto 2010 hot water radiator blower system rather than a straight air heater (say a Webasto Air Top 5500) as they appear more robust and can also heat water for showers etc if required - all a matter of price!
What experience does the group have with this?
 

Phil Herring

Alien
Mar 25, 1997
4,923
- - Bainbridge Island
I prefered the forced air system, as it helped reduce condensation. The radiator system had no positive impact on condensation and took longer to heat the boat.
 

Les

.
May 8, 2004
375
Hunter 27 Bellingham, WA
I agree with Phil. I had a Hunter 40 that I put in the hot water system. It worked well and a side effect was that my lockers that it went through would get warmed. However, I still had a moister problem.

In my past four boats I put in a Webasto hot air system and they have worked well here in the northwest. In my present H27 I have the smallest Wobasto with three outlets and no mildew whatsoever. But better yet, I go down during these winter months, turn on the thermostat and enjoy a lunch, read and (don't tell my wife) take a nap. Fun times.

Give a call to Sure Marine (in Seattle) or go see them during the boat show. They are heating experts.

Good luck.
 

Mikem

.
Dec 20, 2009
823
Hunter 466 Bremerton
I have had a Webasto in my boat for 11 years and love it. On a very cold day it takes about 20 minutes to start heating the boat but the warm forced air certainly feels great as the boat warms up.
 
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Cabin Heat

I finished installing a Wallas 40D diesel furnace in our P42. The unit is installed in the port side stern main deck locker, mounted on the magazine cabinet bulkhead. Seemed to be the best place considering it was close to the stern and the fuel tank, plus it can draw intake air through the opening into the quadrant well that also supplies air to the heat pump. I surface mounted the control panel on the aft cabin port side bulkhead just below and to the left side of the magazine cabinet. I used a three inch hole saw for the registers and a three and one quarter inch hole saw for the ducting.

Everything is connected: fuel, power, control panel, exhaust pipe and warm air ducting and registers. The dealer advised to install the system before ordering the exhaust pipe and sock because of its high cost. One duct and two registers are located in the aft cabin at the base of the double berth, with another duct with two registers in the main cabin port side setee. Since we do not plan on installing a washer/dryer combo I'm going to use the engine compartment vent duct route for part of the warm air ducting.

One duct runs behind the rudder post to registers located at the base of the berthing cabinet port and starboard side. This has worked out pretty well because I can direct heat into the aft head. I installed two registers at the base of the port setee and one under the navigation station.

The new furnace has made a huge difference in cabin comfort for the admiral while on the hook. The system is quiet, efficient and really pumps out the heat. Cold weather comfort should make a big difference during winter cruising.

11/2014 Update: Installed the Wallas 40D diesel furnace in March 2006. Have not touched the unit since then, but have used it many times to keep the interior warm during our winter cruises. Simple to operate, thrifty fuel and power consumption and quiet. Unless there is below freezing temperatures outside, a middle thermostat temperature setting is sufficient.
 
Jan 3, 2010
9
Hunter 41AC LA
Thanks Guys Useful input. As a first step am putting in a larger alternator as I am sure that as soon as I put in the cabin heat the next thing will be the batteries will be down! Will look further into forced air where the choice was a Webasto Airtop 5500. Also will go down to the boat show to talk to Sure, who are the people I am dealing with anyway. Will et you know how it works out.
 
Jan 12, 2011
930
Hunter 410 full time cruiser
Thanks Guys Useful input. As a first step am putting in a larger alternator as I am sure that as soon as I put in the cabin heat the next thing will be the batteries will be down! Will look further into forced air where the choice was a Webasto Airtop 5500. Also will go down to the boat show to talk to Sure, who are the people I am dealing with anyway. Will et you know how it works out.
You putting in larger batteries to go with that new alternator? Wouldn't make any difference if you battery capacity can not accept the higher amps (I have never seen my stock alternator do its' rated capacity because the battery bank can not accept that much).

You sure you need a 5500 and that it isn't going to short cycle too much?
 
Jan 3, 2010
9
Hunter 41AC LA
The aim of the larger alternator is to be able to re-charge the batteries as soon as on the hook on finish of sailing, by running the engine in neutral at reasonably high revs and with a decent load on it - for the shortest possible period. As a consequence will fit a serpentine belt kit at the same time and a smart controller. I have had occasions when simply the auto pilot and instruments will run the batteries down on a long sailing day and I am generally too lazy to hand sail it all the time. It is not a problem for weekend sails, as it goes back on the mains on the slip after the weekend, but on one week to two week trips, the batteries tend to drop off. Once that is done will see where I am as not keen on adding more weight above deck with solar or wind generator if this is all I need to do. I do have a 1kW generator I can carry, but prefer to do without the noise etc.

In terms of the heater size, I am off to the boat show tomorrow to talk to Sure (Seattle) about Webasto and also to Trotac (Victoria based) who do the Wallas. Not sure how big a heater I want and the 5500 was the one that fit the boat size on the chart. Again, may settle for a slightly smaller one to stop it cycling in and out, but first need to take a look at the P&I D's for the boat and where everything goes before final decision.
Ideally want to pull off the main diesel tank as I have a main tank and smaller reserve tank system on the boat. Will discuss with the experts and then see what is the best deal.

Keeping a Canadian registered boat in the US is a nightmare as if I buy something in Canada I have to take it through US customs and declare it and then fit it to the boat. If I buy the heater in the US and fit it in the US I am then SUPPOSED to declare it in Canada as it has added to the value of the boat and is taxable! The boat has to be registered in Canada, despite being kept in the US, as since I am Canadian if I cruise in Canadian waters with a US registered boat in my name they can seize it or charge me the tax etc. if they want to! So for me the easiest is to get the parts in the US shipped to Point Roberts and then simply fit them myself and develop amnesia when in Canada.
 
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Boat Heater

The Wallas 30D is probably a bit small for your boat volume. We have the 40D and it seems to work fine. Our volume a bit more than yours. If it were my boat I would go with the 40D.

It would help if I knew the size of your house bank in terms of total amps, your style of cruising during those months you need to run the furnace and other appliances that draw from the house bank.

We've done a number of week long winter cruises and always seem to have enough on hand even with the furnace running 24/7. Our bank has a total of 480 amps, which gives us 240-250 before recharge.
 
May 7, 2012
1,567
Hunter e33 Maple Bay, BC
I want to put some cabin heat into my 41AC. I am baed in Point Roberts in the Pacific Northwest and adding some heat in the cabin will extend my boating season. I am looking at a Webasto 2010 hot water radiator blower system rather than a straight air heater (say a Webasto Air Top 5500) as they appear more robust and can also heat water for showers etc if required - all a matter of price! What experience does the group have with this?
Love the ability to heat hot water for dishes and a cockpit shower.
 
Jan 3, 2010
9
Hunter 41AC LA
Terry, I am presuming that the only real difference between a 42AC and the passage is the raised cabin roof. I have two 8D batteries for house which at 220amps each gives me 440 amps. The logic for the larger alternator is best explained in an article on the following web site. http://marinesmartenergy.com/product-support/frequently-asked-questions/

Right now I am moving back towards air heat based on the advice of the correspondents above and so will discuss with the various alternatives with the dealers at the boat show. Realistically if the guys are getting all the heat they need with say a Wallas 40, which gives out 13,600 btu's or for more heat the Webasto 5500 which is 18,000 BTU's. both use 75mm or 90mm ducting, and while the manufacturers would recommend the next size heater up this seems to me to be overkill.

At least I now have some idea about what I am discussing with the Reps. The water heating system is lovely, but at least 2.5 times as expensive, so out!
 
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Boat Furnace

One advantage with our boat is that it came equipped with an 8kw Onan Genset. Very handy when it comes time to charge the two 8D AGMs. Usually, the house bank provides enough power for two days of being on the hook. Even with the fridge and freezer on 24/7, the furnace draw is so small that every other day works for us.

Running the Genset for 1.5 hours brings the house bank to about 90%. During that time we also heat water for washing and any electrical cooking. Having just an alternator does extend the charge time considerably.
 
Jan 3, 2010
9
Hunter 41AC LA
OK, I visited the Boat show and having looked at all three alternatives - the Wallas 40D, the Webasto Hot water system and the Webasto Airtop 5500, the winner for me is the Wallas 40D. While it is a bit smaller than the 5500, it is much quieter, it draws its return air from within the cabin, it has two inlets and two outlets, so uses 3 inch distribution duct and as such will be much easier to install. Finally, the Hot water system is around US$4600, plus a lengthy and much more difficult installation process, mostly to mount the radiators etc, and on top of this to actually capture some of the hot water for hot water use is probably going to cost another $1,000. The 5500 costs US$4300, plus a few add ons. The winner is the Wallas, because it is also the cheapest! It is currently C$4000 inc taxes. I expect there will be some add on's, but this would be the same for all the set ups. Right now they are offering the Wallas for 10% off within 2 weeks of the boat show; so despite the performance to actually buy the stuff in Canada and then ship it into Point Roberts, (US) it will be worth the effort. Finally, looking at all three units, there is probably 10-12 hours to fit the Wallas, 15 plus hours to fit the 5500 and probably 30-40 hours to fit the hot water system. I know this is my time, but as an aging mining engineer, I am a believer in the KISS principle, so the Wallas wins. - This was not necessarily what I expected, but thanks to you all for your input.

Terry, on your Wallas, I saw you have it in the Port main locker in the cockpit. Where does it exhaust to and did you put any protection in to prevent possible wave/water ingress?
 
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Wallas Furnace

The installation instructions provided by the distributor/manufacturer covers most everything you need to know. The short piece of exhaust pipe from the furnace discharges through the standard bulkhead transom step fitting. The pipe is installed with an eight inch loop to help prevent sea water ingress.

I do not have any pictures of the install, but I plan on going to the boat this weekend and if it works out will take some and post them here.

The article that I posted earlier here is also in the Hunter Owner Modifications tab above under 42. You will need a couple different sizes of hole saws; one for the three inch ducting and one for the registers. Most everything fell into place. The hardest part was installing the duct work through the assorted bulkheads. Even with as much room as we have, things were pretty tight.

We've been very happy with our 40D. If you like my e-mail address is "thcpmc8269@frontier.com for direct communications. We can also do post replies here.

As I recall it took me about ten to twelve hours to do the entire project; not all at once. The dealer tried to talk me into installing the furnace in the engine room and I'm glad I did not. Not enough room, plus I did not want engine room odors permeating the cabins. The port side transom locker was close to the fuel tank, well protected from the elements and pretty good access to creating the two duct routes.

We have five registers; two in the aft cabin one at the nav station and two in the main cabin. I may add another into the forward cabin at some point, but we seldom use it.
 
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Wallas 40D

I like things simple. When I installed the Wallas 40D on our boat a few years ago the admiral and I talked about where to locate the thermostat. What we agreed on was the bulkhead right next to where she sleeps. Close to the furnace and easy to reach without getting out of bed.

So, at first light, she or I reach over and flip the switch and we go back for 40 more winks. The furnace turns itself on, does self diagnostics, begins to draw fuel, ignites and warms the boat. After the interior starts to become comfortable (about 30 minutes) we wake and start our day.

When it's really cold outside we will leave the furnace on all night on low so the warm up time in the morning is shorter.
 
Last edited:
Dec 25, 2000
5,941
Hunter Passage 42 Shelter Bay, WA
Wallas 40D Furnace

This weekend I drove to the boat to take some pictures of the Wallas 40D furnace that I installed in 2006. The admiral and I have enjoyed the comfort it produces on those cool and cold winter cruises around PNW waters.

The top two left pics show the exhaust stack hose with heat sock and a loop as advised by the manufacturer to prevent sea water ingress.
 

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Jan 3, 2010
9
Hunter 41AC LA
I bought the Wallas 40 D from Scan Marine Equipment, who were very helpful and quick to supply. The heater is now installed! It took about 20 hrs altogether, much of which was spent upside down in the rear lazarette. However, it all went in well and is now working. The kit was excellent with the exception of the tiny torix screws that hold the control box on the wall and which I replaced with regular screws, on which I painted the heads to match. In terms of heat, it is slow to get there, but inexorable, heating the boat up from around high forties to mid 60’s in about an hour, and will apparently go on up from there. Apart from some anxious moments drilling into the fuel tank and also through the back of the boat for the exhaust, plus the need for adding another breaker to the panel to switch the unit, plus the problems of routing the cables and heat tubes, this is not a difficult job to do - it just needs patience and a lot of coffee and pauses for thought before cutting anything!

In terms of heat, it is slow to get there, but inexorable, heating the boat up from around high forties to mid 60’s in about an hour, and will apparently go on up from there.

Overall I am very pleased with the job and the heater and it has official approval from the Disaster control and avoidance officer on the boat who also felt it was a worthwhile addition!

Thanks to all for the comments etc.
Malcolm Swallow - Point Roberts WA
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
I agree with Terry Cox.... do your research and you will find the wallas to have the lowest 24hr power consumption, and is also easy on fuel... and quiet.

for your boat you WILL need the 40 and NOT the 30.... I installed a 30dt on our boat (34ft) 2 months ago, and it has 6 settings... using it by itself in 30-31 degree temps we need to run it on high, full time... but we still have the force10 bulkhead heater, so with the force10 on low, we can turn down the wallas to 4 and keep it warm enough to have a hatch board out....

in the temps we have had in the portland, oregon area in the past two weeks, we have ran the wallas by itself on 4 in the daytime and turn it down to 2 at night. and that is keeping the boat warmer than I think is comfortable, but my wife thinks different:D

I also agree with what Phil said about the ventilation... never underestimate the necessity for positive ventilation.

I mounted the wallis high at the foot of the quarter berth, and with our layout, that allowed me to run a vent line all the way to the front of the vberth.... the other vent comes out below the drawers of the chart table cabinet.
having this warm dry air flowing completely thru the boat gives it a much more "homey" feeling and instead of the blankets feeling a bit clammy in the early morning hours, we are now dry and warm without even the slightest bit of condensate overhead....
this isnt due to the heat, but is directly due to the ventilation...

in my opinion, installing forced air heating with positive ventilation and having the ducts running only to the salon area, is doing yourself and the heating system an injustice.
for the best effect, take the strongest of the ducts all the way forward as this will ventilate and warm the entire boat, which if we didnt need warm dry air distributed throughout the boat, we could heat with the 3 burners of the stove top splendidly well:D

Im very happy we went the wallas rather than the wabasto...