Going Hydronic...pulled the pin today.

Jan 12, 2016
268
Hunter 410 Ladysmith, BC
After months of research, we've pulled the pin and ordered all the parts for installing an Espar Hydronic heating system on our boat. We are excited to get started and expect we will complete the install in the first week of March.

Why hydronic? This was the hardest decision to make versus forced air.

1) Our boat, (Hunter 410) would need at least 20'+ of 4 inch duct work running from the stern forward, followed by another 15+' of 3 inch duct to ensure that our forward pullman berth and forward head had adequate airflow to heat properly if we chose forced air. There is no easy way to make this happen. Instead with hydronic we're running .75" hotwater line from stern to bow and back. It won't be simple, but we'll get a much cleaner install.

2) Having 3 different heating zones. We're putting in three heater cores, each will have short two out put ducts that have small computer fans (low DC draw) to move air. Three heater cores mean three zones for cabin temperatures. ie) The forward berth can be kept cool, the main cabin warm, and the aft berth very warm. With forced air we wouldn't get this option.

3) Heating the hot water tank. This is a real bonus on the hook that hydronic does.

4) It is the quietest system.

The biggest negative I can see is that it won't heat the boat as quickly, nor will it dry a boat out as efficiently forced air. We already have a decent dehumidifier that we use when on the dock. and the boat has excellent ventilation with good dorades, and lots of hatches so I'm not really concerned. I've spoke with one other own of a Hunter 410 who has had an Espar Hydronic on his boat for years and has said it has worked brilliantly and is cheap to maintain.

We've found a very highly recommended local installer who is going to let us assist with the installation to help keep our costs down. Our plan is one heater core under the aft berth, one under the starboard settee, and one under the forward pullman. The sleeping cabins will have one duct run for the cabin, and one to the respective head while the mainsalon will get two output ducts/vents.

Once work starts if anyone is interested I can post up some photos of the work. Also if anyone has done this job before and can make some recommendations I'm all ears. I've read pretty much every thread on this topic here, as well as numerous other forums. Looking forward to having a four season boat.
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I think it was a recent This Old House that had some new heat supply registers. They each had a module run on 3 AA batteries. You could control them with a phone app to open or close to adjust the heat delivered to each room. You'll probably see them soon at West:biggrin:
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
Heating the hot water tank. This is a real bonus on the hook that hydronic does.
Yes, and a primary one for many folks who are often off shorepower. Makes a BIG difference in the decision making process depending on where and how you sail, and the supporting electrical system if hot water is desired/required when not plugged in. Good choice for you and a fine explanation, thanks. Pictures would be awesome.
 
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Sep 22, 2009
134
Hunter 36 Seattle, WA
We did this on our H36 last April, but went with the Webasto DBW 2010. Did not regret it. We're full time cruisers in the pacific NW. Also have 3 zones using the REAL units. Make one of your zones the head, and get the heater outlet near the seat. We also added an air outlet under the settee table, fed by the main cabin unit. We supplemented with a 1500w electric for those really cold mornings at dock. The qualitative improvement on the heat is terrific! I had fun helping to install it.
 
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Jan 12, 2016
268
Hunter 410 Ladysmith, BC
We are getting each head heated with a single duct from a heater core that will be split with a sleeping cabin.
We really liked the units from Espar, Huricane and Webasto. I had no interest in the Planar/Russian stuff.

We ended up choosing Espar over Webasto only because it was easiest to get serviced here locally, I viewed them as equals quality wise. The Huricane stuff was really nice, but too much for our needs as non-livabords. Had we been livabords I think the Huricane would have won the day. The Huricane unit is quite a bit larger as well and would have been more difficult installing in the same location we chose for the Espar.
 

splax

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Nov 12, 2012
692
Hunter 34 Portsmouth
Please excuse my ignorance, but you haven't mentioned how you heat the water on the hook.
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
Please excuse my ignorance, but you haven't mentioned how you heat the water on the hook.
Using the coolant loop that normally runs from the engine to the hotwater tank. You can either run the loop from the hotwater tank to the engine, the hydronic line running through the boat to the various heater cores, or both depending on the complexity of installation you go for. We're keeping it simple. The hotwater tank will be heated via electrics, or hydronic only. It will no longer get heat from the engine loop.
 
Dec 28, 2010
462
Catalina 380 san pedro
I have considered some sort of hot water loop that can tie into the engine cooling system using an automotive off the shelf heater core. Looks like someone already took care of that. Feeling a bit stupid right now.
 
May 7, 2012
1,338
Hunter e33 Maple Bay, BC
We're keeping it simple. The hotwater tank will be heated via electrics, or hydronic only. It will no longer get heat from the engine loop.
I agreed with all of your posts until I got to this fella. I sail in the same waters as you, 3 seasons vice 4. I have a 3 zoned Espar hydronic system and for the domestic hot water alone, I would not give it up. But, I see no good reason not to continue using the surplus heat from your engine to provide domestic hot water. With the addition of 2 valves and a few feet of rubber hose, I would suggest you reconsider. Not a great inconvenience, as we switch the 2 valves located near the hot water tank to "Engine" when we start the diesel and switch back the 2 valves to "Espar" when we shut the engine down. No need to run the Espar if you have just come to anchor or mooring buoy. The Espar is fairly power efficient; however, the engine is free heat. Also I would recommend you talk to your system designer/installer about a summer time loop. There will be many times in the summer when you want hot water for showers or dishes but want no heat. Yes you can electrically turn off the 3 zone heat exchangers but there is still a tremendous lost of heat and energy to get the Espar coolant to the forward end of the boat, back through the hot water tank and then back to the furnace. Again a couple of valves for summertime use only will greatly reduce the heat loss (thus bringing the tank up to temperature much quicker) and energy loss (both diesel and power).
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
. But, I see no good reason not to continue using the surplus heat from your engine to provide domestic hot water. ... Also I would recommend you talk to your system designer/installer about a summer time loop.
Hello, Hello Below;

The reason for removing it off the engine in our case comes down to where the hotwater tank is placed in the cabin. There are built in hose run areas in the bilge area that have just enough clearance for what we are looking at doing. If we are to add an additional run, the cost of the valves and hose aren't the concern. The concern is the need to cut a foot long channel to run the extra hoses below the floor in the galley area to access the hot water tank. Cutting up my fibreglass below the floor boards for anything more than an inch hole for a hose run is a non-starter. As we are planning it now, there will be no need to cut any holes at all to run everything.

Now a summer time loop is something that we are considering, but we will make that decision at installation time. It's a want, not a need at this point. My hope is that we can install the valves and hose for a summer bypass loop near the Espar unit itself.
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
So two days of work accomplished so far...

Espar, exhaust, expansion tank all mounted.

Foil/rubber backed engine foam put in the locker where the boiler resides. We also ordered a muffler with the exhaust so we're hoping that it will be quiet. All the exhaust is wrapped with fibreglass exhaust wrap to keep the locker cool, and prevent accidental burns.

3/4" heavy duty hose has been run to all 4 heater cores, plus the hotwater heater. Getting hoses to both the engine and the hydronic to the hotwater heater was not possible without cutting up the pan. As it is, we haven't needed to cut any holes for all the 3/4" inch lines and wiring.

Main cabin will have two small 6000 BTU heater cores, each with two outlet hoses. The forward and aft sleeping cabins also have a two outlet core with one servicing the cabin, and the other its respective head.

We have moved the hotwater tank 3" to starboard and have made room for a summer time loop with a single three position ball valve.

We are giving each heater core its own fan power switch with a three position toggle (hi/off/low) switch. The power for all switches is in parallel fed by the Espar unit. If all 4 heater cores are powered fan off, the fluid will still flow through each to the hotwater tank without heating the cabin. (The summer time loop doesn't isolate the aft cabin heater core, but does remove the other three.)

The thermostat is mounted higher up in the main salon by the chart table. The circuit breaker is not meant to be used to power on/off the system, so it has been placed below the chart table near the cb's for the windlass and electric winch. It is wired onto the hot battery bus to avoid power being taken away from the system by accidentally cycling the battery switch while in operation.

We've pretty much have ripped apart the interior. One thing I've taken away from this project so far is how incredibly well thought out the systems are by Hunter, and how good the access is. There was a spare conduit with a channel in the bilge pan that made bring our power supply and thermostat wire from the stern most locker to the chart table very simple and straight forward. With the rear mattress lifted I can lift out the entire centre line of the floor and bed base from the engine prop/shaft all the way to the rear most bulkhead. We've been able to lay out over 100' of 3/4" heavy duty hose from bow to stern without cutting the bilge pan, bulked or anywhere else for that matter. Having owned an early 80's full keeler, and helped lots of friends work on their boats, I can't stop smiling as when I tear open something on this boat, it almost always leads to a good news Easter Egg of some other small well thought out bit of design that I haven't taken notice of yet.
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
A neat tip my installer showed me is to tape the end of the hot water hose before pushing it through. He has seen DIY installs where the hose picked up gunk in the hose while being pulled through the boat, and it ended up blocking the lines inside the heater core. He has taped the hose end with electrical tape each time.

The other smart idea he showed me was to have a small wet vac ready when removing the coolant lines off the engine/ hot water tank. We spilled less than a shot glass of old coolant by sucking the old hose dry with the wet vac.
 
May 7, 2012
1,338
Hunter e33 Maple Bay, BC
Good write up lurker. It sounds like you and the installer are working well together. I will recommend the obvious, if you don't already have them fitted and that is CO alarms/detectors. The furnace is normally run for heating purposes when it is cold and the boat is shut down tight. I think Hunter went a little crazy in 2012 and put 3 in the 33e that year. Please let me know what the installer recommends for a fuel filter probably inline. Mine is fed from the main fuel tank directly to Espar. Not good but got away with it so far.
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
Planning on adding dual smoke/CO2 alarm in the aft cabin, I forgot to ask today about the fuel filter. The combustion is all done in the aft most port locker. We're block the ductwork with foam that is roughed in for the air conditioning that is not installed. Very little air if any for combustion will be sourced from the cabin itself by design. Also we have two large dorades mid-cabin overhead that I always leave open for air exchange.

There will be a simple line fuel filter as well, but I can't remember the part#. Finished the plumbing and electrical runs today. Fuel will be tomorrow or Tuesday. I'll post up pictures once completed.
 
Apr 4, 2016
201
Newport 28 Richardson Marina
The biggest negative I can see is that it won't heat the boat as quickly, nor will it dry a boat out as efficiently forced air. We already have a decent dehumidifier that we use when on the dock.

This is not true, I have installed hundreds of home hydronic systems and I believe they actually preform dehimudification better than forced air albeit differently. I hope your experience is the same.
 
Jan 12, 2016
268
Hunter 410 Ladysmith, BC
Lurker, I have the identical Espar controller that your photo shows but I don't recognize the min/max rheostat that is located directly below it. Can you help me out and explain the purpose for it?

Thanks.
Hi Hello Below,

It's a volume control for the speaker output in just the main cabin. We have the same rheostat/knob at the helm, and in the aft cabin.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I am also looking at putting the Espar D5 in my Catalina. Where do you get the fan/coil heaters. I have looked for sources but most are really big with high 12v amperage.