2022 Tab 320 BD, use Alde heater with plumbing drained?

kottum

We have a couple of mornings forecast with possible hard freeze here in Minnesota, then we are leaving next week on an extended trip.  Can I drain the plumbing and still use the Alde heater to keep the interior warm?  

More specifically, will draining the plumbing also drain the Alde water heater and therefore damage the water heater section when turned on?  Propane or electric Alde supply make any difference?

Douglas

dsfdogs

@kottum with the 320, if you drain the hot water line it will also drain the Alde, although I always flip the yellow pressure relief valve as well.

No problem running the Alde on electric or propane without water in the tank. The glycol heats up and will circulate around the trailer for your cabin heat. If there were water in the tank, then it would heat up as well. It's an all-in-one system (heat/water) vs others that have separate hot water heater from heating system.

Yoshi_TAB

Hi, Here's a picture of how it works. The Alde transfer fluid is heated in the boiler either by the propane burner or an electric element. The central heating tubes circulate the Alde fluid around the TAB to heat the cabin.  The water tank (blue in the picture) is seperate from alde fluid and moves via a pump.  The cold water comes in at the bottom and out as hot water at the top.  The alde transfer fluid in the boiler heats the water.  When you drain the Alde, you are only draining the water (blue).  The transfer fluid is still there to heat the cabin.

kottum

Thanks to all, what a great forum group!  

Douglas

kottum

So here's the plan for getting through the hard freeze (two nights forecasted) without full winterization.  This may also be useful on our travels next week.

Drain the hot and cold water lines.  Let the (full) fresh water tank drain with a slight dribble through the night, thereby protecting the tank drain valve without emptying the tank.  Heat the 2022 Tab 320 BD cabin with the propane/Alde system.  I've got two 100 amp Battle Born lithium batteries in the exterior front tub, understanding that they have circuitry to protect themselves from charging when below freezing.

What do you experienced Tab folks think?  Many years of RV'ing here but first time with Alde and lithium batteries in freezing temp's.

Douglas

pthomas745

You should consider "how cold will it get, and how long will it stay that way".  Just a quick skim at MSP and Duluth forecasts, and I don't see any "freezing" temps.  (or maybe I'm missing something). These kind of questions come up a lot.  Learn the "blow out" method of winterizing and you can do the blow out in 20 minutes, and be ready to "de-winterize" very easily.  And...there will be no worrying. Winterizing is easier than worrying. 

Unless your "extended trip" is in a southern state, this situation will come up again in the next month.  Being prepared to winterize on the road will help you out a lot. 

Winterizing 104 has a rundown of both methods. 

https://tab-rv.vanillacommunity.com/discussion/comment/175594/#Comment_175594

kottum

Thanks pthomas, the blowout method is excellent if we actually need it.  Our local forecast for west/central Minnesota has been predicting lows anywhere from 23 to 32 degrees early Friday morning, now trending higher than a couple of days ago.  

Our route next week will be somewhat weather dependent and most probably consist of several nights boon docking on the first leg, about 15 days total to our place in Arizona for the winter.  We plan to head for Monterey, Ca and follow the coastal highway to San Diego, camping at military installations along the way.

Douglas

Denny16

Sounds like a plan, but in the SoCal area, parts of the coastal highway no longer exist as a highway, from Oceanside to DelMar, most of old highway 1 is a state campground in places, other parts are under iInterstste Hwy 5.  Have fun, and stay safe.
 Cheers 

Sharon_is_SAM

@dsfdogs and @kottum - just a correction, the Alde water tank hot water line exits the top of the tank, so the hot water low point drain does not drain the Alde water tank, it only drains the hot water plumbing lines.  The Alde cold water supply line enters the bottom of the tank and the TaB cold water low point drain can drain the Alde tank.  The Alde Safety/Drain valve is within the Alde cold water supply line.  There is a valve that allows air to enter at the top of the Alde water tank to assist emptying.  It may be helpful to open a hot tap to insure air enters the tank.  I would add that Alde says to use the Alde Safety/Drain valve (yellow flapper) to drain the tank.  

@kottum - we ran into your situation on our visit to Moab.  We had just dewinterized our CSS and the weather changed.  Knowing it takes a long time for a large tank of water to freeze, we drained the Alde and low point drains, left the water tank full, kept the heat on, added antifreeze to the shower P trap, gray and black tanks.  The areas most at risk are under the TaB away from the heat- the fresh water tank outlet and drain, shower P trap, and waste tank gate valves.  Knowing that the temperature was due to rise quickly and thaw anything that may have iced over, we just waited to use the plumbing.  Not sure if letting the fresh water drain drip will do anything as the valve outlet is quite small - not like a larger house faucet/outlet.  If anything, in the event that the drain freezes, just avoid using it until it thaws.

Denny16

I second what Sharon said.  However, on newer TaBs, all the plumbing is inside the TaB, above the floor, and if the Alde is left on heating, the cabin to a temp above freezing, the plumbing will be fine and will not freeze.  A CSS with its u heated external galley would be the exception, and I would dump some antifreeze into the sink drain, and if at a camping facility with holding tank dump point, drain the gray and black tanks, adding enough antifreeze to get some in the tank drain valve.

If you are using the Alde for heat, you can leave water in the water tank and water lines on non CSS model TaBs, as the Alde will keep the hot water tanks from freezing (Alde control panel hot water in normal (one arrow) setting), even if the temp in the cabin drops to 30F.   The PEX water lines will also tolerate a short exposure to temps in the 30s without breaking.  

So if the temperature drops overnight to 28-32 range, keep the Alde on to around 40-50F or higher, and camp on.  A short overnight drop in temperature should not cause any issues.  Even the black and gray tanks (as long as they are not completely full) should be fine, but a bit of antifreeze down the gray water drain would not go amiss for extra protection.  The black tank (and toilet cassette) are above the floor and will get heat from the Alde heating the cabin.
 Cheers 

MarkAl

I agree with the above suggestions. In addition, the Pex is somewhat tolerant of freezing but the joints are mostly cheap plastic and can crack and produce leaks. Also no one commented if you're driving through freezing weather, the inside trailer cools VERY quickly. Some leave the propane ON w/ the heater but it generally is not recommended.  Also I've found it always advisable especially when fringe or winter camping like you're doing to check for leaks (pop the cushions and feel around) for leaks on a daily basis. We camp through the winter such as it is in the Seattle area and frequently get creative in how and when we winterize as we travel/camp. I have replaced a few plastic connections with either Sharkbites or brass fittings for small leaks. I've not specifically found my winter use has caused the leaks or just the vibration of use but be warned. Small leaks so far have been my only issues with damage to the water system. We use the blow out and anti-freeze in the traps method and generally are liberal with filling the traps with anti-freeze to get some in the gray tank to drip out the valve. Also with the Cassette, clear the water line (flush with air pressure) and coat the toilet valve w/ some anti-freeze. Toilet and outside shower are specifically on my don't forget list. 

I now carry a Pex repair kit in my tools.