Forced Air Diesel Heater Exhaust Pipe

[CaptTom]

The new forced air diesel heater works great! But...

First time running it, the exhaust pipe got up to a certain temperature then began smoking. I had a fiberglass sleeve on the pipe, which I'd ordered along with the pipe. Could this have been the source of the smoke?

I shut it down, and ordered some proper heat shield exhaust pipe insulation.

But meanwhile I'm wondering, Is this normal? Should I just wait until whatever it was burns off, or should I strip off the fiberglass sleeve and start over with the quality insulation?

Word to anyone installing one of these: those exhaust pipes get HOT!

 

[psneeld]

Hot enough to flash off anything on the tube, hot enough to warrant the fiberglass sleeve, hot tnough to discolor the stanless exhaust outlet....but not hot enough to start a fire if properly installed, nothing is stored against the tube and proper airflow is available.


I have a Wallas DT - 40 and it really doesn't get that hot unless on high for hours when there is little wind.


mine is mounted under the helm seat in a cabinet where the top of the heater is within a foot of the top of the cabinet. Once it was on a test run and the exhaust hose was off as I forgot to stick it on or it came off...the cabinet got very hot inside but there was no scorching of the wood above or even a real burning smell.

 

[ksanders]

The first time you run the furnace oils left over from the manufacturing process are going to burn off.

The fiberglass sleeve that comes with the pipe is just fine.

 

[sunchaser]

Safety first. What does the manufacturer say the heater exhaust pipe temperature should be and where measured? What is yours?

 

[CaptTom]

Today I ran a quick test: I took a section of exhaust pipe I'd cut off during the installation, and directed a propane torch at it.

I could easily get the same amount of smoke, with the same smell, as I had observed during the first firing of the furnace. This happened with and without the fiberglass sleeve.

The good news is the smoke stopped after the residual machining oils had burned off, and the fiberglass seemed none the worse for the overheating.

The plan now is to run the furnace up to temperature again, this time giving it a few minutes for the oils to burn off the exhaust, watching closely and monitoring the temperature. Unfortunately, the manual does not give specifics for exhaust temperature. I still plan to install the better insulation I ordered, as one more layer of protection.

 

[DavidM]

That exhaust pipe can easily get up to 500-600 degrees F. These furnaces unlike home heating oil furnaces are not very efficient. So lots of heat goes up the stack, and thus the temperatures are high.


Perfectly normal.


David

 

[Rebel112r]

What make of heater is it?

 

[Al]

Echo Rebel- What is the brand? We have the DT-30 Wallas. We installed as required with exhaust 12 inches above the furnace location. We had the initial smoke smell as explained within the instructions. Following a single initial burn cycle all was right with the world. We can hold our hand on the exhaust, while warm, not red hot to the touch. That includes any long burn run.

Al-Ketchkan

 

[ksanders]

The Wallas exhaust wont get hot because it is a tube within a tube design.

The inner tube is exhaust and the outer tube is combustion air.

Many other brands utilize a single tube exhaust which can get really hot. Thats why the fiberglass sock the OP was refering to.

 

[Al]

Correct Ksanders I forgot that feature, once installed and fired all forgotten!!
Just a great maintenance free unit.

Al-Ketchikan

 

[psneeld]

The 2 smaller Wallas models do have the tube within a tube exhause...but the Wallas DT-40 only has a single tube exhaust with fiberglass sleeve....at least for the last 3 years.


Still waiting to hear which make/model Capt Tom has.

 

[CaptTom]

OK, OK. I wasn't going to spill this until I was satisfied it was working.

I took a chance and bought the Russian-made Planar 4KW (13,600BTU/H) unit on Amazon for under $650. Similar name brand units I looked at cost a lot more, and for me this is not a necessity. I figure, if anyone knows about cold, it's the Russians!

It came with all kinds of cool Cyrillic writing and Russian Post Office stickers on the box. The manual was obviously translated to English, but not as badly as some I've seen. They got a couple of colors wrong on the wiring diagram, but enough were correct that I figured out the rest. I'll probably re-write the operating instructions myself just so it's clear to me and anyone else using the controller.

On burn #2 the exhaust got up to around 550° F (290° C) at the point closest to the unit. That part didn't smoke at all, and the rest of it had also pretty much burned off by the time I shut it down.

At around 38°F outside, with doors and hatches open, the cabin warmed up very quickly. This thing is going to make it significantly easier to spend the night on the hook during spring and fall.

I'm going to do one more closely monitored burn-off at full power, then add a layer of exhaust insulation and play around with the controller to see how it runs at other power levels.

My final upgrade will be to add a pump to allow me to transfer fuel from any of my diesel tanks directly to the small heater day tank. I've always wanted the ability to transfer between tanks anyway; this just requires one more valve and some hose.

 

[ksanders]

OK, OK. I wasn't going to spill this until I was satisfied it was working.

I took a chance and bought the Russian-made Planar 4KW (13,600BTU/H) unit on Amazon for under $650. Similar name brand units I looked at cost a lot more, and for me this is not a necessity. I figure, if anyone knows about cold, it's the Russians!

It came with all kinds of cool Cyrillic writing and Russian Post Office stickers on the box. The manual was obviously translated to English, but not as badly as some I've seen. They got a couple of colors wrong on the wiring diagram, but enough were correct that I figured out the rest. I'll probably re-write the operating instructions myself just so it's clear to me and anyone else using the controller.

On burn #2 the exhaust got up to around 550° F (290° C) at the point closest to the unit. That part didn't smoke at all, and the rest of it had also pretty much burned off by the time I shut it down.

At around 38°F outside, with doors and hatches open, the cabin warmed up very quickly. This thing is going to make it significantly easier to spend the night on the hook during spring and fall.

I'm going to do one more closely monitored burn-off at full power, then add a layer of exhaust insulation and play around with the controller to see how it runs at other power levels.

My final upgrade will be to add a pump to allow me to transfer fuel from any of my diesel tanks directly to the small heater day tank. I've always wanted the ability to transfer between tanks anyway; this just requires one more valve and some hose.

Thats fantastic! A little competition is a very good thing!

everybody that I've heard of that took a chance on those Ruski units was very happy they did!

 

[FF]

Russians are not known for customer service , so you might purchase a couple heaters more for parts while you can.

The Espars are famous for needing parts annually ,

 

[tallswede]

Wow, sounds like a great unit, would love to see your installation when you get done.

Kevin

 

[CaptTom]

Russians are not known for customer service , so you might purchase a couple heaters more for parts while you can.

The Espars are famous for needing parts annually

An annual checkup makes a lot of sense, my home oil boiler gets one. As for parts, they are available, mostly from outlets in Europe and Canada. The manual has some detailed diagrams. And again, this is not a critical component to me; I've gotten by all these years without one.

I'm running it on kerosene for now, but I'll switch to diesel if I start using it a lot. Then back to kero before any prolonged lay-up. That should help keep things clean. Also, the manual says to run it for at least five minutes every month, even if it's warm out. Interesting that they felt the need to add that last bit. I plan to follow that advice.

Wow, sounds like a great unit, would love to see your installation when you get done.

You might regret asking. There isn't much to show. The only thing visible in the cabin will be the hot air vent, and outside just a small fitting on the transom. Here's a look under the drawers in the aft cabin:

And from the front (still with the drawers removed):

 

[Rebel112r]

If that picture is right side up, then the Espars are mounted 180 degrees differently. Air in and exhaust out mounted facing down on the Espar. Any moisture in that set-up would dribble into exchanger causing white smoke on start up, and possible corrosion.

 

[Rebel112r]

After looking at pic again, I see that we are looking down on it. Dont know if this orientation, is approved by Planer or not. Espar requires the combustion intake and exhaust to be down.

 

[CaptTom]

After looking at pic again, I see that we are looking down on it. Dont know if this orientation, is approved by Planer or not. Espar requires the combustion intake and exhaust to be down.

I know I've seen similar references for other brands, not sure about Espar. But this excerpt from the Planar manual is pretty clear. Basically, the igniter is angled at 45 degrees into the combustion chamber, so you can mount it anywhere within the 90 degree arc that leaves the igniter more or less "up".

 

[Romanp]

Please advise

I'm surveying a boat right now with a planar heater installed. Part of the exhaust pipe is not insulated. Apparently installer had told the seller during the installation, do not insulate the last leg,so it can dissipate the heat and not melt the side of the boat where the exhaust pipe connects to the boat. Please advise, should I insulate the rest of the pipe ? Would it cause the damage where the exhaust is mounted to the side of the boat ?

 

[Nomad Willy]

Rompamp,
It may be true depending on the exhaust design.

I have a Wabasto and the thru-hull for the exhaust is a specially designed unit that insulates enough so the outer edges don’t get too hot for the FG hull.
The Plannar heater is made in Russia. I have no idea how good they are. How far is it from the heater main unit to the thru-hull of the exhaust? Mine is at the maximum length from the heater. I’m sure the exhaust temp is the same on all heaters of this type except for output in btu. But the exhaust at the heater should be the same. Have you seen the Wabasto through-hull? If so how similar is it to the Plannar? I’ve never heard of anyone having trouble like burning fiberglass.

If you know the output of the Plannar you could buy a through-hull from Sure Marine in Seattle and easily substitute that for the Russian part.
FYI the first trawler I had I installed a Wabasto in it and it was the shortest allowable allowed by Wabasto specs. It went through the hull-side only a few inches from the heater exhaust.

Is there a service record for this boat and if so are the number of hours run known? Sounds like it’s been run for sometime and you may be good to go. But if it's readily accessible you could take a temp reading and see if that’s low enough for FG. Somebody here ought to know that off the top of their head.

In the short of it I wouldn’t worry much about it.
You may find a Plannar dealer in the US ??
I read something about Plannar but can’t remember.

 

[Alaskan Sea-Duction]

Question: Do these unit put moisture in the air? I have observed fogging of windows with these units?

 

[Nomad Willy]

Asd,
We have not found that to be true.
Sure is when we run the stove though.

 

[CaptTom]

I'm surveying a boat right now with a planar heater installed. Part of the exhaust pipe is not insulated. Apparently installer had told the seller during the installation, do not insulate the last leg,so it can dissipate the heat and not melt the side of the boat where the exhaust pipe connects to the boat. Please advise, should I insulate the rest of the pipe ? Would it cause the damage where the exhaust is mounted to the side of the boat ?

Presumably the installer knew something. Mine is insulated all the way to the end, and no melted fiberglass. The exhaust through-hull is designed with an air gap and the outside part, which mounts to the hull, stays cool. But maybe with a very short exhaust hose it could be a problem. Those hoses do get HOT!

 

[Alaskan Sea-Duction]

Asd,
We have not found that to be true.
Sure is when we run the stove though.

I am thinking of a Wallas so I can run it while underway. Space is a concern.

Are the exhausts loud? Some at the dock you can hear several docks away.

 

[Ted]

I am thinking of a Wallas so I can run it while underway. Space is a concern.

Are the exhausts loud? Some at the dock you can hear several docks away.

Contact ksanders Kevin is using Wallas

 

[Nomad Willy]

ASD I don’t think my Wabasto is loud but some say they are. We have our exhaust outlet on the stern. I often run it at our moorage and all through the winter I go down to the boat and start the Basto and because it’s cold I come back to my car where I can see my boat. I read a book for 15 minutes at which time I go down to the boat. It’s warm by then and I hear the Bastos exhaust. I marvel how quiet it is but others may not agree. I think it can be said it makes more noise than a Wallas. I think it’s quiet but if I was at an anchorage the noise would surely travel across the water. All sounds do including the Basto. But in the same anchorage in the afternoon other boaters probably wouldn’t hear it.
As I’ve said it’s noisy in some circumstances but over-all not objectionable .. to me. My wife has had problems at times but she’s a very light sleeper and has never suggested we turn off the Basto.
One needs to start and run the heater briefly about once a month or it won’t start. I once considered that a problem but now (and for some time) just run it ever several weeks. No problem in the winter and no problem in the summer.
After running the Basto for several years it wouldn’t start so I took it to Sure Marine for servicing. They said it was badly sooted or/and carboned up and suggested I switch to kerosene fuel. I did. It’s run flawlessly since but the kerosene dance is not entirely welcome. Kerosene is expensive and we need to get 2 gallon jugs filled, stow them in the hold, monitor the status of fuel and keep the day tank from running out. Not that bad and I have no intentions of going back to diesel or looking for another heater. Happy with our Wabasto.

I should add underway when it’s cool or cold we Run the Basto all the time. Usually I don’t know it’s running. I step out on the aft deck and think “oh yea I’ve got the heater on” when the cold air hits me in the face. That’s wonderful. I turn it on and literally forget it and it’s warm all the time.

Also if I wanted to I could probably go back to diesel from the main tank and take the unit in for servicing every year.

 

[ksanders]

I am thinking of a Wallas so I can run it while underway. Space is a concern.

Are the exhausts loud? Some at the dock you can hear several docks away.

The wallas are desd quiet. They are a drip pot type combustion chamber.

Units like the ESPAR are gun type combustion where fuel gets injected into a high velocity air stream. By design these are very loud because of the air flow.

 

[FF]

Just remember GRP if ignited is not easy to put out.

 

[Marco Flamingo]

The good stainless exhaust through-hulls are a double wall design that doesn't pass much heat to the surrounding hull. I have them on two boats, both with completely insulated exhaust pipes, and I've never had any problems with the area around the through-hull getting too hot. The exhaust temperature is enough to melt a fender (so I've been told), but surprisingly little heat is passed through the double wall fitting.

I just replaced an old Webasto with a new diesel heater. I was able to use most of the old installation with some modification. The Webasto had a fresh air intake that ran a tube about 10 feet to a through-hull fitting on the side of the cabin. Long runs of either the intake or the exhaust reduce the efficiency of these little heaters, so I eliminated that. I now take in combustion air from the ER (just like the engine). That allowed me to put a noise reduction fitting on the intake (which helps with the whining noise).

Even better was adding an exhaust muffler. The Webasto made a hideous whine, most notable when in my slip with a boat next to me. The tiny stainless mufflers that come with some of the cheaper "parking heaters" like on Ebay are not for use in living spaces. The leak exhaust. I fabricated one (a straight through "glass pack" style) as shown in this picture. My heater is now basically silent. I can hear the ticking of the pump when things are completely quiet, but that's it. People walking down the dock can't hear it.
A big change from not having a muffler.

A long run of uninsulated exhaust pipe is possible if you have somewhere that nothing will ever get up against it. That is questionable on most installations. The other downside is that a longer uninsulated run might slowly build condensation during intermittent use. If this puddles up in a low point and limits flow, there will be a problem. These heaters are sensitive to intake and exhaust restrictions. Soot buildup and intermittent firings seem to be mostly caused my air flow restrictions.

Mark