Rixen Comfort Hot Installation and Pics

[Dick Simonis]

For those of you with the Hurricane system, you might find this accessory to be beneficial....I sure have.

The Comfort Hot is an add-on water tank with two 2,000 watt electric heating elements, thermostat, and over temp protection.  Each element is control by a switch so you can run one (30A service) or two (50A service)  Jim added the switch in the closet right around the corner for the AC breaker panel.  Power comes from the AC breaker so each switch actually selects either Heat or AC.

The Comfort Hot tank went into the engine room between the inlet air box/hose and a sidewall behind the air inlet....really nice fit and only the front cover protrudes for access to the electrics.  There is no connection between the Comfort Hot and the Hurricane Brain Box so installation was relatively straight forward.

Inside the Hurricane control panel, Jim installs a diode pac that allows the circulation pump to run as soon as any zone calls for heat.  In our case we opted to not include the HW heater as one of the zones.  This bypasses the Hurricane remote on/off switch inside the coach.  NOTE:  There is a downside to this installation though.  Whenever a thermostat call for heat, the circulation pump runs whether of not the Comfort Hot is energized.  This could be a problem if you store the coach and leave the thermostat in the heat position...including the bay heater.  The circulation pump will come on and run forever.  I'm thinking about a couple of voltage sensing relays tied to the diode pack power in lead to help compensate for a "senior moment".

When we arrive on Sunday after 7 feathers a 50A power cord and parking behind the shop was provided...a bit hard to find the shop but OK.  The installation was completed by early PM on Monday and we were on our way.  While in Deer Park, WA the weather turned nasty with ran and low temp into the 30's so we had ample opportunity to use the new installation.  It is wonderful and coupled with our retrofitted digital thermostat have keep the coach withing 1 degree of the set point and that's with the air handlers at low speed.

Underway, the thermostats still control the temp using the engine heat exchanger but without having to use the preheat switch and going through SW Montana last week it was cold outside but inside it was like never having left the RV park.

For heating hot water,  we truly have endless hot water as long as the system is running...I tried real hard to run out and never had to even adjust the mixture control.  In some circumstance you might have to "fool" the unit by leaving one of the zone fan switch in the "off" position to the zone continues to call for heat.

Regular Hurricane operation is not affected except that with both on, the burner does not run very much since the fluid is already heater to ~160F or so by the electric elements so using both in very cold weather is quite efficient.

Another thing I noted is that the circulation pump becomes the heart of the system and will get a lot of running time.  Mine had an intermittent running problem in Deer Park (probably brushes) that caused some anxiety so I ordered a new on from Jim.  I will overhaul the old one and keep it for a spare.  FYI, the motor unbolts form the liquid end so it's not to tough to change out.

Overall, while not perfect due to a lack of interlocks, it's a great unit and well worth the cost.  I will be using mine while parked alongside the house during the AZ cold snaps into the 20's.  Last year I burned 1/2 tank of fuel keeping coach above freezing.

Dick

[Joel Weiss]

Looks very nice. What's the approximate cost?

[Dick Simonis]

It was a tad over $1500 OTD.

We're hanging around Idaho Falls for a bit and snow is in the forecast so it should get workout. Beats the bejeepers out of our electric space heaters since the heat is so evenly distributed and I have yet to run the burner.

Dick

[Joel Weiss]

We just had a Comfort Hot installed by Rixen today.  I have to say that rarely am I as impressed by a person and his business as I was by Jim Rixen.  The place may have the general appearance of a garage shop, but don't be misled; there is a high degree of professionalism at work there.  The Comfort Hot system is an impressive package, as are all the items I was shown.  As Dick has already described the installation was fast, neat and the cost was as promised.  He even cleaned my coked up Hurricane for a very fair price.  All the work was complete by the end of the day as promised.  

We had our system installed a bit differently than Dick did.  We wanted it to come if any of the zones, including hot water, called for heat, but Jim wanted to make sure we didn't overtax the system by making hot water if, for example, we wanted to maintain a comfortable temp while we were away for a few weeks.  So he repurposed the no longer needed "Preheat" switch to become the "hot water" switch.  Now we can control if we want the Hurricane or the Comfort Hot to respond to heat calls from the hot water sensor.  Between the "hot water switch" and the hot water tank breaker we can determine if hot water is heated by the tank heating element, the Comfort Hot/Hurricane, or both.

One thing not mentioned in Dick's post is that I've calculated that the Comfort Hot will pay for itself rather quickly.  Except for the RV park we stay at for the winter months, none of the other parks we frequent have charged us for electric usage.  In the 3 years we've owned the coach we've run the Hurricane ~2,000 hours.  If 2/3 of those hours were at parks other than our winter one that would amount to ~1,340 hours.  At 1/3 gallon of fuel per hour that's 442 gallons which at $4/gal comes to $1768 in diesel fuel burned which will be replaced by "free" electricity used by the Comfort Hot.  Coincidentally $1768 is just slightly more than I paid for the system; so a 2-4 year payback is not an unrealistic expectation.

[Joel Weiss]

Since this has started off by being a fairly cold winter, I thought folks might be interested in knowing how Rixen's Comfort Hot was standing up to the challenge.  

It's good that I had Jim install the new system since the Hurricane died again a few days after Jim cleaned it.  Clearly, something else is wrong with it, but with my Comfort Heat available I'm not all that concerned.  Rixen claims that his system will keep the MH warm as long as the outside temps stay in the mid-upper 20's, but we were plenty warm in Gallup NM on the way to TX when it was 20F outside that morning.

One nice aspect about using Rixen's system is that it is almost totally silent since all you hear is the sound of the baseboard circulating fans.  Yesterday, on a very blustery day with temps in the low 40's and winds running ~30 mph I did find it helpful to switch the fans to high, but that was really to better circulate the warm air and pass more of it through the heating coils.  We've not yet been in a situation in which the heating capability of the system was being overtaxed.

Based on the assumption that Rixen installed twin 2,000 watt heating elements, I've calculated that the system has roughly half the effective BTU capacity of the Hurricane's burner.  At the end of the month, when I pay for the electricity I've used, I'll get a sense of what kind of duty cycle the heaters are experiencing.  Jim inspected my circulating pump's brushes and there should be no problem with them going another several seasons before they have to be replaced.

I guess when the weather gets a bit better I'll take a look at the Hurricane to see if I can figure out what's wrong.  Both Rixen and Kevin Lambert at ITR have offered their  telephone assistance.  But, honestly, there is little urgency to fixing it.  It's a lot easier to use electricity to heat the MH during the winter than having to lug jerry cans of diesel fuel to keep the tank topped off.  And ~$4/gallon diesel isn't such a cheap heat source.  And my DW keeps pointing out how nice and quiet the new system is; no more "roaring" diesel-fired furnace in the middle of the night.

Rixen does have his own replacement diesel-fired heater that would fit in the Hurricane's footprint.  It's a nice system with an easily removable "head unit" that contains the pump, burner, etc.  So servicing it would be a lot easier than having to disconnect the Hurricane and drag its "box" to an accessible location.  Rixen's system is ~$4k installed and does not include the Comfort Hot electric backup.

[Dick Simonis]

Joel, Your experience pretty much mirrors mine.  After the comfort hot install I had some rather cold weather in Montana and Idaho.  I found that it would maintain an inside temp of around 70 when it was in the low 20's outside.  The only time I had to run the boiler was early in the morning when I wanted to bring the temp up from 66 (sleeping temp) to 72.  The electric alone was just too slow so a boost from the boiler was useful.  The upside is the diesel ran a lot less and once up to temp I could shut it off.

Since we don't full time the savings won't be as great but last year I burned well over 1/2 tank of fuel keeping the coach above freezing.  This year I will keep the Comfort Hot on one element with the thermostat set at 50 while it's in the 20's than flip the other element on when it dips into the teens.  I do have 50A service at the house so I'll see how this works.  I figure the electric bill will go up but that's OK since I'll have a lot more peace of mind and not have to worry about a Hurricane malfunction.

I'm still thinking about a control that will not allow the recirc pump to run unless there is either voltage to the elements or heat in the tank.

[Joel Weiss]

Dick:

Just a suggestion that you might be better off leaving both heating elements on all the time, regardless of outside temperature.  Heat is heat, so if it takes a certain amount of energy to maintain the coach's temp given a particular outside temp, then if you have only one element working it will take twice as long to generate that amount of heat.  Therefore, your circulating fans will run longer because there will be less energy in the heating fluid.  It isn't going to cost any additional to leave them both on.

As for the circulating pump, my understanding is that it runs when any of the thermostats calls for heat. I included the hot water aquastat in my system, but with a dashboard switch that I can shut off if don't want to have it heating the water.  I'm not sure what you're proposing; the pump shouldn't be running unless the system is calling for heat.

Joel

[Dick Simonis]

Joel,

You may be correct on the heating elements...guess I didn't think that through completely.  As for my sense circuit, since we don't full time it's possible for the system to call for heat when the elements are not powered up.  I.e. if the temp falls below ~45 F, the bay heater may command heat and and there is none.  In this circumstance the recirc pump will run unnecessarily.  The other circumstance would be if the owner has a brain *(^@ and accidentally leaves one or more thermostats set for heat.

In my view, that's the biggest failing with the system design, there is no on/off capability and I didn't think about that during the installation.  There seems to be room inside the Comfort Hot for another snap thermostat using the existing mounting lugs.  If so, it should be easy to use a N.O. surface mount thermostat set for ~90 F or so with wires to the DC common for the the relay harness the Jim installed.

At least that's what my thinking is as of the moment.  I need to speak with Jim and get his take on the matter.

[Joel Weiss]

Dick:

The thermostat heat/off/cool switches become the master switches for the Rixen system.  If you don't have the heating elements powered then just turn the thermostats to "OFF" and they won't call for heat and, therefore, the pump won't run.  

There are only two thermostats you can't directly control, one is the aquastat on the hot water tank and the other is the one in the basement designed to prevent freezing.  You chose not to have the hot water aquastat trigger a call for heat so the pump didn't run when the system wasn't powered up; I chose to have Rixen install a dashboard switch so I can either have the system make hot water or not.  The only one not directly under my control is the basement one and a switch could easily be installed to cut that one out if we wanted to do it.

Joel