Plumbing an Espar Hydronic 4 heater

[Robthebrit]

Whats the best way for me to install this water heater, i want it to be used for hot water and a coolant heater. If I install both the hot water heat exchanger and heater on the coolant circuit it will serve its dual purpose and I get free hot water while driving. My question to those who currently use these heaters is how much heat do you loose when its cold by having it continually circulate the coolant circuit rather than a self contained system.

What stops the thermostat opening and letting hot water go through the radiator? The manual is no use because it doesn't tell you how to install it on a 352 and I don't understand the coolant circuits on the engines that it does give info for.

Rob

 

[Robthebrit]

I got it from lubrication specialists. The manuals that come with it explain how to install it on a number of domestic trucks and a few imports such as the fuso and sprinter, you can get kits with all parts for these trucks. All it says for generic installs are take the water from a low high pressure location such as the block and return it to a low pressure such as the suction side of the water pump. It doesn't say anything about avoiding the thermostat.

I can't be the first person to install one of these on an OM352.

Rob

 

[lowenbrau]

I'm not sure i understand your question. The primary purpose for me it to heat the engine block. In the coldest conditions (-30 and worse) the unit still cycles off after running for an hour or less. 17,000BTU is enough to handle the engine heating plus any other reasonable uses you have for it. In my case, I generally plumb it in such a way that the heat goes to the heater core first and then returns through the block to the heater. That way I get heat in the vents, clearing the windshield as soon as the unit starts working. I also make sure not to waste the exhaust heat. I plumb it so it aims at the engine oil pan. This makes the engine very happy when you start it.

I've never seen the coolant temp exceed 160F in the block with the Webasto heating it so the t-stat never opens.

 

[Robthebrit]

I want to use the unit primarily as a heat source for the camper, if plumbed into the coolant circuit it will also give a secondary benefits of keeping the block warm and providing hot water while driving. This is also the simplest install.

The problem is while parked the heater will be on all the time to generate hot water and heat for the camper but I don't want all the of heat in the coolant to be lost via the block. The engine has 7-8 gallons of coolant in it and I simply can't see the heater keeping it all warm especially when 95% of it is outside. Yes it will keep the coolant warm enough to warm the block but I don't think its going to be warm enough to serve its purpose as a camper heater.

This is why I am considering a second circuit that is self contained within the camper. This is what Stephen Stuart did on his mog but you lose the benefit of free hot water while driving and you lose the option of warming the block. Connecting the two circuits with a water to water heat exchanger would provide the ability to heat the coolant and provide free hot water while driving. This exchanger would be plumbed so it could be by passed when parked and block heating is not required. A couple of hours before you drive open the exchanger valve and turn on a coolant pump and over a couple of hours you'll warm the coolant. This is way more expensive, less efficient and more complicated, but it is more reliable because the coolant circuit is only modified with a heat exchanger and everything stays in the engine bay.

The mog has an ether start and it'll start in the coldest weather but its brutally hard on the engine.

Does that make sense?

Rob

 

[OutbacKamper]

Rob;
I had mine installed by the pros at an actual Espar dealer, so I can't help too much with specifics. However I can tell you that these guys found it difficult too, as they had never installed one on a Ford F350 before and the F350 installation kit that Espar told us was available turned out to be discontinued. The generic schematics showed so many different options that they were just confusing.

My goal was to install the heater to provide engine and cab preheat and to run a seperate circuit to my camper to provide heat to a fan coil and a heat exchanger for hot water.

At first the Espar would not circulate the coolant enough to the camper circuit, but we solved that by adding a ball valve that when closed would force the coolant to run thru the camper. This worked well. The engine always seemed to get sufficient heat even in very cold weather, but the long coolant lines running to the camper should have been insulated. You could notice the reduction in heat output when the weather got below about -10C.

Good luck with your install, please post some pics of you heat and hotwater setup when you get the chance.

Cheers
Mark

 

[OutbacKamper]

Rob;
I did not get to read your most recent post prior to my first post, so please bear with me:

I think my complaint about loss of heat (in the camper) during cold weather illustrates exactly what you are describing in your post. I talked about adding insulation to the coolant lines, but as you point out the engine itself is also radiating heat ...and there is no way to insulate that!

If I were to start again I would install the Espar in the camper, not in the engine compartment. This makes for a much simpler install with the added benefit of a removable camper still having a heat scource. I am thinking of a set-up similar to what Darrin Fnk used on his Mog camper. You could add a second circuit to the engine, with a shut off and quick disconnects (if camper is removable) for occasional engine preheating when necessary - however when engine preheating you would loose a lot of heat in your camper loop. You would not have to use a heat exchanger between the 2 circuits as long as you use the same coolant in both circuits.

Cheers
Mark

 

[FusoFG]

I mounted my espar d5 at the rear of the truck under the camper attached to a frame cross member.

I inserted 2 wyes in the hoses to the truck cab heater core and ran 2 coolant hoses from thoses wyes to the espar.

What kind of water heater are you using?

I have a 6 gallon marine hot water heater that has both a built in engine coolant heat exchanger as well as a 110v heating element.

Marine hot water heaters that are made to connect to an engine for their heat source have a mechanical thermostatic mixing valve between the cold water inlet and the hot water outlet to regulate the hot water temperature.

Water heated to engine coolant temperature is much hotter than a household hot water heater makes.

I connected the hot water tank heat exchanger between the hoses running between the espar and the engine.

I also connected 2 radiators in series between the 2 hoses running between the espar and engine. Each radiator has a 2 speed 12v fan.

I think hvac guys call it a parallel series circuit.

I have 2 valves in the system.

A ball valve in the hose coming from the engine and a valve in series with the 2 camper heaters.

With both valves open and the engine running it circulates engine coolant through the hot water tank and I get free hot water while I drive.

There is still plenty of hot water for showers the next morning.

Coolant also circulates through the 2 camper heaters and when we stop for a break the camper is nice and toasty.

With the engine stopped and the espar running the hot water tank is heated, the camper heaters produce heat and the engine gets heated as well.

If I close the valve to the engine, I get hot water and camper heat, but no engine preheat.

If I close the valve to the camper heaters (in the summer) I get hot water when either the espar or engine is running.

If its cold and you are using the espar for camper heat there will always be hot water in the hot water tank.

If its summer and you've sitting so long that the engine heated hot water has cooled down ( 2 days or so), turning the espar on for 10 - 20 minutes will heat up the hot water tank for showers, dishes, etc.

When it's cold and we've been using the espar for heat and we want engine preheat, we just open the engine valve an hour or so before starting - while we shower and eat - and the block with be warm.

You haven't mentioned how you are going to control the espar.

Did you buy the timer? We did and it's useful for preheating the engine or running the espar for 20 minutes to heat shower water.

And it's a must when you need to read the diagnostic codes.

But it's not so useful to heat the camper unless you like sleeping in a good sleeping bag and just have the espar come on in the morning and warm the camper in the morning before you get out of bed.

But for any real comfort you will need a thermostat.

Get a programmable one at Home Depot that has batteries so it has it's own power.

I connected a double throw switch in the yellow wire that runs between the timer and the espar. That's the lead that tells the espar to stop and start.

I connected the espar side to the center, the timer to one pole and the thermostats heat lead to the other leg.

That way I can control the heater with either the timer or the thermostat.

I also connected the relay that runs the camper heater fans to the thermostat heat lead.

With the switch set to connect the thermostat to the espar,when the thermostat calls for heat, the espar comes on and the fans start. Once the thermostat is satisfied it shuts down the espar and the fans.

When it's 15F outside and 65F inside, the espar runs about 8-10 minutes each half hour.

When we are driving in cold weather, I set the switch to the timer position so the espar won't come on and the termostat turns the fans on and off to maintain any temperature we want in the camper as we drive.

Tips:

Use stainless steel hose clamps - check with a magnet. If the hose barbs are long enough use 2 clamps per connection. Best stuff would be silicone coolant hose and constant tension clamps.

try to keep everything lower than the radiator cap so you can bleed the air out of the coolant hoses.

Set the lag on the thermostat to it's maximum value so the espar doesn't start and stop everytime the temperature changes a half degree.

Don't put a valve in each hose to the engine, just one hose. That way the radiator will serve as the expansion tank for the coolant when the espar is running even if you aren't preheating the engine.

If you are thinking of disconnecting the camper from the truck and running the espar, you will need an expansion tank with a radiator cap on the camper side to handle coolant expansion.

Get the muffler, untill the espar drops down to low speed, it's loud. I don't know about the d4 though.

I haven't insulated the 2 hoses running between the espar and the engine yet because heat loss hasn't been a problem. But I'm thinking about it.

Tom

 

[charlieaarons]

For what it's worth, a very experienced hydronic heater repair man recommends Webasto over Espar. He says Espars have problems sometimes with bearings wearing out, but he thinks Webastos are pretty troubleproof. He works here in Anchorage and installs units in trucks used on the North Slope, so he sees a lot of units with a lot of use.
My particular setup has two totally isolated systems: 5kw Webasto Thermo Top C for the camper and a 9kw Webasto for the block and cab.

Charlie

 

[KMR]

Soooooo, how much do these magic boxes tend to run?
Websites don't seem to list any prices.........

 

[Jeep]

Soooooo, how much do these magic boxes tend to run?
Websites don't seem to list any prices.........

A D5 will run around $1400 to $1800 anywhere in Canada. They will heat up to a 600 CID engine. There is probably not enough price difference to use a D4. We installed 19 this month alone, fantastic product. I save over $150 per month in fuel in my Dodge.

Fuso FG...excellent thinking on the integration of a thermostat and water radiators. I was just about to buy an Airtronic for an interior heater!

I would insulate the coolant lines on longer runs, I think it would minimize any heat loss.

 

[lowenbrau]

For what it's worth, a very experienced hydronic heater repair man recommends Webasto over Espar. He says Espars have problems sometimes with bearings wearing out, but he thinks Webastos are pretty troubleproof. He works here in Anchorage and installs units in trucks used on the North Slope, so he sees a lot of units with a lot of use.
My particular setup has two totally isolated systems: 5kw Webasto Thermo Top C for the camper and a 9kw Webasto for the block and cab.

Charlie

I started out with a Pro Heat (very large) and moved to Webastos about 9 years ago. I still have the first one I bought and it has never given me any trouble. I was lead to believe that Espar was more field serviceable and thus gets more use in the military. I think either one is good.

As far as prices go, I can get a TSL17 with a timer for about $1250cdn these days which is way down from what they used to be, thanks to the stronger loonie I guess.

 

[yabanja]

Just contacted Webasto regarding their thermo top evo unit. They don't sell to the public-only authorized installers.

Allan

 

[Kiomon]

One thing to be aware of, is that Webasto is very dealer centric and they dont really deal with end users when it comes to service. So if you have a problem with a Webasto item; they will send you back to your dealer for troubleshooting. Sounds minor, but it's a big contrast to Espar, Dometic, and others who will try and help you as an end user. I received a DOA Webasto x100 Cooktop and it was an absolute nightmare to get replaced.

 

[Joe917]

These guys had the best price I found in Canada : http://www.iandmelectric.com/products/webasto-tsl-17-engine-pre-heater-12-volt.
We ended up purchasing the unit from Wajax as they are local and matched the price. Their initial price was ridiculous.
We are running a very similar set up to the one Tom described in his Fuso. The differences being we have 2 large radiators with no fans in the living area and no timer or thermostat. All lines are heater hose until they enter the living space where they switch to pex. All exterior lines are insulated.
There is a manual valve that separates the engine circuit from the system. Engine heat is very effective for heating the hot water tank, in summer we just close the radiator valves. It is rare that we use the electric element.
Our living space is 127 sq/ft and very well insulated.
The system is original to the truck (23yrs) I replaced the heater as the old one was getting very temperamental. The water tank also just failed and I have replaced it with a brand new Isotemp Spa tank.
We have run the system in as low as -10C very comfortably.
Cheers Joe.