Me Too

[Dr Bill]

I have owned a 1985 or maybe 1986 25H twin bed, center bath for 3 years.

I have taken it across the SW US for three trips, and one to NC.

I have had good success with my upgrades and repairs, and am very happy with how it has behaved.
My largest changes were (1) to pull the sofa and table from the front, and replace it with two benches that faced each other each with a side window behind them, with a table on the end between them.
(2) to remove the squirrel cage central heating unit, convert the cabinet to storage, and install two catalytic heaters, one in the LR facing the front, mounted on the refrigerator side, and the other in the bathroom, up high. The bathroom vents nicely out the ceiling vent. The LR unit has an aluminum 'inverted U manifold' that I made, which captures the exhaust gas from the heater and ports it out into the vented space behind the fridge. This way I can heat the unit without having to use battery power, and without risk of CO buildup in the unit.

We mostly boondock/dry camp, so I needed to reduce the impact on the battery of the heater. I also have a CPAP that pulls the battery down, so I have a portable solar panel.

[silverloaf]

Interesting about the CPAP. I assume you were using an inverter to get 110V out of 12V?

Also interesting about the catalytic heaters. Got any pictures and specs to share?

I'm reconstructing a 1988 30P. A tankless water heater arrived today. Have you given any thought to this?

Bob

[KYAvion]

What type of tankless heater did you get?

[silverloaf]

I purchased an Atwood OD50 on-demand water heater. My son-in-law installed one in their '06 travel trailer and was pretty happy with it.

I've read mixed reviews about its performance. Some of it has to do with minimum water flow requirements. When retrofitting, Atwood's Tech Support says to remove all low flow faucet heads to reduce restrictions. The other has to do with the procedure when calling for hot water at the tap.

Since I'm replacing all the plumbing and pump, I'm going to re-engineer the system to minimize system flow restrictions. I'm told the Truma tankless water heater is the cat's meow. But I not prepared to pay $2500 to have idiot-proof hot water.

[KYAvion]

Other than removing low flow fixtures, what other restrictions are there to eliminate? As far as boondocking and running off the freshwater tank, I wonder what effect the absence of low flow heads will have on your water usage.

Sounds like a nice upgrade. I wonder if there'd be issues having it operate in tandem with an existing 6 gal water heater?

[Dr Bill]

The cat heaters are a "wave 3" in the bath, mounted high on the wall, and a "wave 6" in the LR. The wave 6 has the manifold to port the exhaust outside.

The CPAP is actually a BiPap, and while I have been using a 200W inverter, the Resmed S9 uses 24V, and the current system involves 12 -> 120 -> 24, and that seems like too much conversion loss, even though I don't use the humidifier. Resmed has an optional 12 - to 24 converter that I just purchased, and I will use that from this point on.

I thought about a tankless heater for the water, and would be interested in your experience. At this point, to be honest, my interest in replacing the water heater has two dampers: (a) the current heater is fairly new and working well, and (b) the delay in heating plus the small capacity tends to reduce the temptation by my lovely wife to take longer, frequent showers (and we only use the water heater for showers).

[silverloaf]

I would have considered a tank-type water heater. But I was able to find the Atwood tankless for $700 plus shipping. Other suppliers wanted $950-$1200.

We might be living in this trailer for awhile after we sell our home. We aren't sure where we are going to end up.The upgrades we are doing is to support the possibility of more than just weekend junkets.

Regarding flow restriction, the OEM plumbing is 1/2" with many tees. Every tee is a restriction; the 1/2" tubing becomes 3/8" at best. I'm going to use 3/4" PEX for distribution and reduce down to 1/2" for branch circuits to keep the low-restriction fixture heads.

I don't see the advantage of using tankless and tank-type water heaters in tandem. The tank-type activates on temp drop while the tankless activates on pressure drop. Most tank-type heaters are rated at 8500-9000 btu; the tankless is rated at 50,000 btu.

I'll keep you posted.