Fresh/Holding Tank Heaters - Relay?

[GyroGypsy]

The tank heaters on my 2018 Navion are not working. I don't know how long it has been this way. But I installed a Victron battery monitor and did not see any house battery current draw when I turned them on. I think it should be about 16.5 amps total per the heating pad marking, 5.5 amp per pad. I have the WGO schematics, but see no relay. I suspect there must be one somewhere due to the current limitation on the back-lit switch. WGO customer support is closed for Good Friday.

I have voltage on the switch, no voltage at the heating pad, and verified that the pad has a good ground connection.

Anybody know if there is a relay, or else a cable connector that may be the issue? Where is it physically located?

[Winterbagoal]

I haven't tried mine yet, but they were installed after delivery by the dealer. I'm in Canada, and we aren't allowed to receive the units here with them connected at the factory.
I didn't observe the installation, but all the wiring underneath was not paticularly well protected. I used some wiring conduit I purchased at a hardware store to wrap everything up to better protect it.
I'm assuming here, but I don't think they did anything special to connect the wiring, but I'm not sure. Unfortunately, it's a bit chilly here, or I'd try to see where they connected the various wire runs under my unit.
If you have a heated garage/storage shed to work in, try getting underneath and have a look. It may be that something yanked one or more of the wires loose under your unit. I'm sure that mine would come loose fairly easily, if I hadn't added the conduit.

[GyroGypsy]

I have checked underneath. The pads are properly connected with no hang-downs, and the wiring goes directly into the coach floor from below. It appears near the fixed bathroom wall, adjacent to the slide out wall. I don't see a good way to view within the wall for servicing, and would be surprised to find a relay there. It might be one of the boxes found below the bottom kitchen counter drawers? According to the schematics, thete should at least be a connector plug somewhere.

[Winterbagoal]

I guess you'll have to wait until WGO Support re-opens.
Sorry.

[youracman]

Don't know about the newer rigs, but on mine I replaced the WBGO factory-installed pads due to damage, etc. They are the Ultra Heat brand and they are/were the "gold std" at that time and the only ones used by most manufacturers. The pads have a bump on one end and inside that bump is a thermostat. The heaters on mine will not come on until about 40F IIRC. The way I check them out is (per mfg directions) hold an ZipLock with ice cubes on that "bump" area and soon that specific pad will come on.

The reason they want you to always have at least 2" of liquid in the tank is to prevent rapid/recurring cycling of the built in t'stats; ie. early wear out, I assume.

I also have one elbow heater. They only draw about 3A and do not have a t'stat but the draw on my two tank pads plus the elbow heater is about 13A.

YMMV, of course.....hope this helps.

[Old-Biscuit]

Is there a 'lump' on heating pads.......close to edge/where wiring goes in?


Heating pads should be thermostat controlled.......turn on when temps are 40*F and then back off when temp rises to 60*F


Place ice pack on lump and drop temp so thermostat closes

[youracman]

Oh, and BTW: I was never able to find that relay on my rig either. I talked to a tech at WBGO several years ago when I replaced the pads, but they couldn't help me.

[GyroGypsy]

That is discouraging to hear they could not find a relay either. I will recheck my pads for who made them.

I note you are in Denver, any issue when in real cold areas? We have some 20F nights coming up. Will check then.

Is an elbow heater something for human elbows? If not, send link or picture.

[youracman]

You may have better luck at WBGO than I had, I believe my tech was a fairly young guy by the sound of his voice. ('Course they all sound young to me .... as I am 88+ lol.) I have often got a guy on the line who almost seemed like he built my rig ..... most are durned good at their job .... and the price is right too.

I am not a cold weather camper, actually. I am a fair weather, pole-to-pole guy. The original owner had the heaters installed at the factory before he took delivery. Then a replacement by others (a blowout resulted in the black tank being "beat to death" by the steel treads) required a new heater at that location.....before I owned the rig.) Bad workmanship there. Then the adhesive on the FW tank finally gave up, so I replaced that one too. I just want to "be prepared" in case the weather ever surprises me on a Fall or Spring trip.... the Fall being our favorite season to travel.

Here's a link to an elbow heater. I have a few inches of pipe and and elbow at the FW tank outlet before the gate valve. WBGO installed that elbow heater to protect the gate valve at that location and I just went ahead and replaced that one too while I was at it.

https://www.ultraheat.com/ultraheat-...e-elbow-heater

BTW-A lesson learned re the pad heaters for the tanks, I ordered them from a trusted source and 1 of the 3 didn't work on my receiving inspection test. Returned all of them (they disallowed one.....said I caused the failure) and then I talked to the Ultra Heat people. They were not surprised as they said most competitors used a copper deposition type of heat trace ..... Ultra Heat will only use wire.....more expensive, of course but more reliable. Theirs worked fine right out of the box. On second thought, that was just another example of a lesson I guess I have never learned; i.e., the old "you get what you pay for" lesson.

Good times, and safe travel.

BTW-2 We are promised a 15F event Easter night/Monday morning. Ouch.

[GyroGypsy]

Thanks so much for the link and information Youracman. One of my pads has a loose corner and I was just about to Google for what adhesive to use for repair.

Can you easily send me a image of your elbow heater insulation? Did you just wire in in parallel with the pads? So "holding tank heater on" switch REALLY turns the elbow pad on, rather than simply apply power and be internal thermostatically controlled as the pads are. I am inclined to turn the switch on before going to bed, assuming sub-freezing is suspected during that evening.

I have a second test must perform during early tomorrow a.m. cold snap. I just completed installation of two used Tesla S batteries into modified, sealed, and insulated OEM battery box. This gives ~10 kWh storage for $2K plus "incidentals" - my "CoVid-19 Project". Tesla cars use heated antifreeze to maintain above freezing temperature, as well as cooling as needed. Tonight's 20F here will be the first real test of my 50W aquarium heating and pump-based system to maintain 65F at the battery. I may need to upgrade the heater or add more insulation. I'd rather find and fix any installation issues here rather than while on the road with no Amazon Prime delivery!

[Winterbagoal]

If cold weather use is among your priorities, have you ever considered Relion's LT Series batteries? I have 2 of them (RB100-LT) in parallel and they can charge at a (closer to) normal rate down to -4F (-20C). They use a portion of the charging power to self-heat, so that they don't damage themselves. They've been happily charging for most of this past winter in my driveway. I've occasionally drawn them down, and they recharge very quickly, even below freezing.

[youracman]

GyroGypsy: "............Can you easily send me a image of your elbow heater insulation? Did you just wire in in parallel with the pads? So "holding tank heater on" switch REALLY turns the elbow pad on, rather than simply apply power and be internal thermostatically controlled as the pads are. I am inclined to turn the switch on before going to bed, assuming sub-freezing is suspected during that evening."

Actually, my rig is in storage on the other side of Denver and under a bit of snow right now. Someday I may learn to take before and after pics of things like this...wish I had. In any event, yes.....the elbow heater is continuously "ON" when you switch on the tank heaters and it is wired to the same B+ junction as the two tank heaters (I grounded each of the 3 pads locally to the frame for convenience.) The small surface area and small current draw of the elbow heater renders is safe to leave on continuously as I understand it and it will not damage the ABS pipe it is wrapped around.

To insulate that elbow/heater, I used a brand of 2" insulating tape (from an AC wholesale house) but it is the same product as this one available at HD: https://www.homedepot.com/p/Armacell...8230/100539553 It is somewhat "stretchable" so it conforms to the curvature of the elbow well and I used about 6 or 8 Zip Ties to keep it in place ....... especially at the end of the wrap. I have used this tape in AC work and it has held up for years ..... even exposed to the sun and other outdoor elements. The last time I glanced at it under the rig it looked as new.

Best............... ed s

[GyroGypsy]

Originally Posted by Winterbagoal

If cold weather use is among your priorities, have you ever considered Relion's LT Series batteries? I have 2 of them (RB100-LT) in parallel and they can charge at a (closer to) normal rate down to -4F (-20C). They use a portion of the charging power to self-heat, so that they don't damage themselves. They've been happily charging for most of this past winter in my driveway. I've occasionally drawn them down, and they recharge very quickly, even below freezing.

I was considering those. However each Tesla S battery is rated at 233 Ah at 24V, thus 5.2 kWh and available for $1100 compared to the Relion 12.8V/100Ah (1.3 kWh) for $1400. So for slightly less battery cost, my two Teslas provide 10.4 kWh storage vs two Relions giving only 2.6 kWh. The two Teslas are only slightly larger than two Relions, and they fit in the stock battery box below the front entryway. 2 Teslas = 8 Relions in storage capacity. My battery heating system cost less than $100 in parts, plus a gallon of RV antifreeze. I also sealed and insulated the battery box. A lot of fabrication is required, but I had nothing better to do during my Covid lockdown!

[Winterbagoal]

Originally Posted by GyroGypsy

I was considering those. However each Tesla S battery is rated at 233 Ah at 24V, thus 5.2 kWh and available for $1100 compared to the Relion 12.8V/100Ah (1.3 kWh) for $1400. So for slightly less battery cost, my two Teslas provide 10.4 kWh storage vs two Relions giving only 2.6 kWh. The two Teslas are only slightly larger than two Relions, and they fit in the stock battery box below the front entryway. 2 Teslas = 8 Relions in storage capacity. My battery heating system cost less than $100 in parts, plus a gallon of RV antifreeze. I also sealed and insulated the battery box. A lot of fabrication is required, but I had nothing better to do during my Covid lockdown!

It was just a thought. I don't think I have the expertise to create a system like yours. It sounds pretty bleeding edge for RV off grid technology.
Agreed about finding things to occupy the time.