Showing posts with label espar. Show all posts
Showing posts with label espar. Show all posts

Replacing the Glycol Pump

Our Espar heating system suddenly started acting strangely, and when we checked the error codes, we found that it was overheating (error code 14). After diagnosing the problem with Jim Rixen, we found that the upgraded glycol pump from 2020 (with the rotating speed dial on the back) was failing. Rixen said that they've been seeing a fair number of these units fail, and they sent me a new one under warranty. The job in front of me was to drain the glycol out of the system and change the pump.


The Revel's heating system requires Dexcool in a 60/40 ratio, but Jim Rixen said that 50/50 is fine, so I bought a 50/50 solution from Prestone at a regular auto parts store. The system holds a little less than 2 gallons, so I bought 2 of these jugs.


Rixen suggested that I simply loosen one of the hoses going to the Espar furnace and let it trickle into a bucket. This was easy, not messy, and took about 45 minutes.


Since we rotated our dinette seat and have a RoamRig system, it left the side with the pump accessible from behind the driver's seat. I removed the side of the dinette bench, loosened the glycol tank, and rotated it to access the blue glycol pump.


I cut the wires going to the old pump, loosened the clamps, and removed the pump from the two hoses connected to it. There was only a little glycol in the old pump, so a few paper towels cleaned it all up. The new pump is on the left in these pictures, and you can see the black speed dial on the 2020 pump on the right.



The new pump is a 2-speed, and since I have a Revel that with an engine heat exchanger (longer distances to push glycol), Rixen recommended that I put the new pump on high speed. This apparently draws about another amp of power. Instructions show how to wire the pump.



Handy Wago connectors make it very easy to splice into the system - - lift the little lever, insert wire, close lever. Here you can see the white wire joining the brown ones, so this is configured for high speed.


Putting the hoses back on the new pump was difficult, but a heat gun softened the hoses enough to make them pliable. I tightened all the clamps, put the reservoir tank in place, and poured about 2 gallons of glycol into the reservoir (using a funnel). Rixen said that the pump is powerful enough to push all the air bubbles through the line, which it did, and the heater is now functioning properly again.



27-February-2024





Heating System Improvements

After using the heating system in our 2018 Revel for 2.5 years, there were a few improvements that we wanted to make. Since the system was designed by Rixen's Enterprises in Sandy, Oregon, we decided to have them do the work, and we drove the van to Rixen's in July, 2020. 

Our goals were the following:

  1. Replace the stock Winnebago thermostat with a modern, more accurate version;
  2. Relocate the Espar heater to the back of the battery box on the driver's side;
  3. Service the Espar heater;
  4. Replace the somewhat noisy glycol pump with a newer, quieter version;
  5. Add an engine heat exchanger so that we could drive through sub-freezing temperatures without having to use the Espar heater to keep the tanks warm.
All of this was accomplished in about 4 hours, and cost about $950.

A diagram of the heating system, compliments of Bob Fulton from the Revel group on Facebook, shows all the major components, along with the changes that we made on this trip.


The original thermostat was cheap, simple, and highly inaccurate. Rixen's have made a newer version for their system, and while it's a bit more finicky, it's also more accurate, with a 'swing' (hysteresis?) of about +/- 2 degrees.  We're generally happy with it, though it takes some light touches with its touch-sensitive interface. Also, since it's more sensitive, it cycles the furnace much more often than the old thermostat.



It was necessary to relocate the Espar furnace because Winnebago installed them high on the frame during 2018-2019, in an extremely inaccessible location. Thus, if the Espar needed maintenance or troubleshooting, it was very difficult to access. The standard location in newer Revels is to mount it on the back of the driver's side front battery cage, which is what Rixen's did for us, shown here. They also serviced the Espar, replacing the used atomizer screen for the igniter, flushed and replaced the glycol, and found that our altimeter had never been properly wired by Winnebago back in October 2017, when our van was built. We also picked up spare gaskets and atomizer screens in case we need to service the unit in the future. Here is a photo of the Espar in its new location.


Due to its new location, we rerouted the exhaust line, bringing it up higher, and putting it behind the galley window.




The original glycol pump was somewhat whiny, and I want the quietest van I can get. Rixen's newer pump is almost dead silent, and apparently has 2x the power of the previous version, so we had Rixen's install it. In the following photo, it is the blue appliance under the glycol tank. 



Finally, we added a heat exchanger from the engine to the heating system so that we can use the engine's heat instead of running the Espar. This is advantageous when driving through sub-freezing temperatures because it will keep the van's tanks from freezing WITHOUT having to run the Espar furnace. A heat exchanger is installed under the van, just below the glycol tank, and two lines (in & out) are run from the engine's coolant system back to the new exchanger. 

A view of the heat exchanger, with brass fittings, mounted up high along the frame with two lines of coolant running to it from the engine.


Here are a few photos showing the changes that are made to the cooling system under the hood.



The trick for keeping the tanks warm while driving is that the circulation pump must be running, so that is accomplished by turning on the system, setting the thermostat to some high temperature, and turning the fans off. The fans are turned off with the center setting of the fan speed switch. (Note: Bob Fulton improved this kludgey configuration by installing a proper switch - - see the Facebook group for details.)

One point of failure for the heat exchanger is a rupture in the coolant lines that run back to the exchanger, specifically where they are mounted near the engine, where they are susceptible to abrasion. One Revel owner has already found a leak from this, so care must be given to how the lines are mounted. Here is how mine were originally installed - - note the potential for abrasion from the engine lift hook.



I wrapped my lines in an extra layer of hose, and ziptied them to the engine lift hook, shown below. In this way, the extra layer absorbs the abrasion, but this remains a contact point that has to be monitored.



A better way of doing this is Bob Fulton's approach, in which he manufactured an arm to hold the lines free of the vibration. Bob says that to manufacture this arm, "It was an 1" over (part with hole drilled), then 2" up, then 4" over again."



Bob Fulton also made an excellent diagram of the heating system, along with a cheat sheet on how to use it.



Finally, meet Jim Rixen.





14-July-2020

Heater Exhaust Repositioning

Ralph Hill, a member of the Revel Facebook group, has repositioned the the exhaust from the diesel (Espar) heater. He wrote up all the details, and I'm posting it here with his kind permission.


The exhaust from the Espar ends in front of one of the brackets supporting the running board on the driver’s side. It is very vulnerable there. It looks like a stiff bush could do serious damage to it. I have repositioned mine based on a picture I saw of a modification done by Agile Off-Road.

The final result is shown in these pictures.




The beauty of this modification is that no holes need to be drilled and no new hardware is needed. It leaves the Espar exhaust well protected. There is a possible downside. I think there may be some rule that the exhaust from the heater cannot be immediately below an operable window. This modification places the exhaust outlet below the dinette window. The original position is very slightly ahead of the dinette window. I think this makes no difference, but the rules might not see it that way.

To move the exhaust you have to drill out the rivet holding the clamp to the bracket for the running board. I drilled from the rear. Then twist off the cap on the end of the flexible exhaust pipe and slide the clamp off. At this point, part of the rivet is likely to be stuck in the clamp. I pried the clamp open a bit, cut the rivet with a hack saw, and pushed out the remains of the rivet. There might be better ways to get the rivet out. Perhaps drilling from the front might work better.

Next, you have to remove the rear bolt holding the bracket for the running board to the bottom seam of the body.  I needed a 3/8" socket on the bolt and an 11mm 12 pt box wrench on the nut. (“Huh?” you say. Well that is what I had that fit). Run the bolt through the clamp (it will fit if you press while turning). Slide the clamp back on the flexible pipe. Straighten the pipe and adjust the position of the clamp so the bolt lines up with its hole. I tried to position the clamp so that it was tilted very slightly with the bottom further forward than the top. I did this to try to help keep the flexible pipe from rattling against the bracket for the running board. When you have things in position, tighten the nut on the bolt. Turn the nut, not the bolt. If you turn the bolt you will probably twist the clamp. I did that on the first try. Adjust the pipe trying to keep it straight and away from things it might rattle against. Aim the end of the flexible pipe down and out a bit. Thread the end cap back on the pipe.

I finished by spraying all the bolts and the hole for the rivet in the bracket for the running board with a waxy corrosion inhibitor. That is the shiny yellow you see on and around the bolts.