Plastic cap loose in the water heater compartment?

MMouse · 06-25-2021, 11:52 PM

Hi there,
I haven’t turned on the water heat yet in my new 2021 MM 1800BH, because I’m not sure what this off white plastic cap is or where it should go? Dealer walk through didn’t mention it and I just noticed it. (See picture, and apologies if it shows up sideways… the cap is laying on the bottom right). There’s also a sticker on the inside cover of the WH saying “this unit has been winterized”, however I get water from the kitchen sink and toilet just fine and the dealer filled the fresh water tank for us before we hit the road home and said it was fine to be used. Maybe they just come from the factory with that sticker. From this picture, is this WH ready to flip the interior switch to “on” and start getting hot water, or does something need to be prepped or turned on inside the WH itself first? It’s a Dometic.

Also, separate question, could someone share what those two hoses (blue and red) are for sticking out from the bottom of the unit right before the rear bumper?

Thanks in advance, this forum has been immensely helpful and that’s an understatement!

be happy · 06-26-2021, 03:04 AM

The blue and red tubes are most likely "low point " drain hoses. Somewhere you will have a valve to drain the water lines. Those valves are called low point drain valves.

As for the water heater, I really have no idea as to the cap. In looking at the picture at the bottom, it looks like behind the propane line there is a threaded something. Would that cap go there? Have you verified you have water in the water heater itself. If hooked up to city water or with pump on lift the lever on the pressure relief valve and see if water comes out. If no water then your tank is not ready to turn on. You will need to find the water heater bypass valve or valves. These same valves will allow water to all the faucets without going through the water heater.

Good Luck

backtrack15 · 06-26-2021, 07:32 AM

The cap in the water heater is for the drain. You’ll find the drain is currently open (threaded connection near bottom that is just barely visible in your photo). The water heater is probably empty and bypassed right now. The bypass valves are behind the removable panel underneath your sink (left cabinet door).

The blue/red are the low point drains. The valves for these are just above the floor where those blue/red tubes exit. You have to remove the interior panel there under the bottom bunk to get at the valves. I installed a little access door on that panel so I would not have to remove/install it all the time.

Edit: Sorry did not see your full question. Do not turn on the water heater until you've closed that drain (with cap) and filled it completely with water. To fill it, I'd open the relief valve and then open the bypass valves. You'll know it is full when water spills out of the relief valve. The relief valve is the portion with what looks like a circular blue sticker and a little handle (pointed down in your photo). If you pivot the handle so it is pointing straight out (away from the trailer), the relief valve should be open. Close it once the water heater is full.

rgvtexan · 06-26-2021, 08:50 PM

Quote:

Originally Posted by backtrack15

The cap in the water heater is for the drain. You’ll find the drain is currently open (threaded connection near bottom that is just barely visible in your photo). The water heater is probably empty and bypassed right now. The bypass valves are behind the removable panel underneath your sink (left cabinet door).

The blue/red are the low point drains. The valves for these are just above the floor where those blue/red tubes exit. You have to remove the interior panel there under the bottom bunk to get at the valves. I installed a little access door on that panel so I would not have to remove/install it all the time.

Edit: Sorry did not see your full question. Do not turn on the water heater until you've closed that drain (with cap) and filled it completely with water. To fill it, I'd open the relief valve and then open the bypass valves. You'll know it is full when water spills out of the relief valve. The relief valve is the portion with what looks like a circular blue sticker and a little handle (pointed down in your photo). If you pivot the handle so it is pointing straight out (away from the trailer), the relief valve should be open. Close it once the water heater is full.

If you have turned the electric for the heater, you most likely need to replace the electric element. The heater will work on propane with a burned out element. But a bad element can cause problems in your electrical system with leakage currents and possible ground faults.

MMouse · 06-28-2021, 01:35 PM

Quote:

Originally Posted by backtrack15

The cap in the water heater is for the drain. You’ll find the drain is currently open (threaded connection near bottom that is just barely visible in your photo). The water heater is probably empty and bypassed right now. The bypass valves are behind the removable panel underneath your sink (left cabinet door).

The blue/red are the low point drains. The valves for these are just above the floor where those blue/red tubes exit. You have to remove the interior panel there under the bottom bunk to get at the valves. I installed a little access door on that panel so I would not have to remove/install it all the time.

Edit: Sorry did not see your full question. Do not turn on the water heater until you've closed that drain (with cap) and filled it completely with water. To fill it, I'd open the relief valve and then open the bypass valves. You'll know it is full when water spills out of the relief valve. The relief valve is the portion with what looks like a circular blue sticker and a little handle (pointed down in your photo). If you pivot the handle so it is pointing straight out (away from the trailer), the relief valve should be open. Close it once the water heater is full.

Thanks SO much! 🙏 I followed this step by step and got the plug back on (took some help with a wrench, might add thread tape), the right valves open, pump on, WH tank filled, and then fired up. Got hot water in the sink and shower. After reading and re reading the part manuals, I’ve got new questions (pictures below for each)….
1. My tank model appears to be for propane only, as the 12V cord shows “not included with propane only unit” on the manual part list, and there’s no cord coming out of the tank to plug in under the sink. There is, however, an empty electrical outlet next to the tank under there. There’s also a switch on the wall for “water heater-electric”. Possibly a manufacturer mistake to have installed a unit that was propane only? Or is this so I can later upgrade to a different water heater?

2. It sounds like there’s a jet engine in the heater flame when it’s on and lit. It’s bright orange, and a true fire, not a flame. I checked for debris/nests etc in there but nothing. Is there a way to tone down the flame?

3. 12V vs propane fridge… which do I have? It appears I can select which power source, am I reading that correctly?

Thanks! Next step…. A practice run of draining the tanks before our first trip!

backtrack15 · 06-28-2021, 02:29 PM

I'd assume you have the propane fridge there since it has a gas mode. It'll run on propane and electricity (when you have hookups). The 12V fridge (which you do not have) will only run on 12V electricity. The propane fridge face is nearly flush with the cabinetry and the handles stick out. The face of the 12V fridge sticks out ~3" from the cabinetry and the handles are embedded in the side of the door (don't stick out).

The question about the water heater flame adjustment is a good one that I need to look into myself. Mine seems fine at sea level but was loud/flaky at 8000-feet. I assume there is an adjustment but I have not looked into that yet.

It is possible that they installed an LP-only water heater. Parts shortages seem to be leading to some variability during the pandemic. Did you look at the actual model number (hopefully on a sticker somewhere there in the heater) vs the model descriptions? Yours looks very similar to mine in the photo, but I'm just going from memory. On mine the power cord for the water heater comes around from the left side, across the back, and into the plug (when viewed from inside the trailer).

backtrack15 · 06-28-2021, 02:57 PM

Here is a good conceptual video, but I don't recall seeing a sleeve like this that could be adjusted on the Dometic. It's possible that Dometic assumes you'll tune the gas rate instead of the air rate. There is nothing on this in the owner's manual or installation manual that I could find. Maybe someone else here will have some suggestions.

video

MMouse · 06-28-2021, 03:09 PM

Quote:

Originally Posted by backtrack15

Here is a good conceptual video, but I don't recall seeing a sleeve like this that could be adjusted on the Dometic. It's possible that Dometic assumes you'll tune the gas rate instead of the air rate. There is nothing on this in the owner's manual or installation manual that I could find. Maybe someone else here will have some suggestions.

video

Thanks! I saw the same video but correct… no air intake piece to adjust in the dometic. In other news, I felt around inside the tank insulation and discovered the power cord hiding! I was able to get it to the plug, so that mystery is solved. ��
Hopefully someone else has experience with the flame adjustment, and thanks for the confirmation on fridge type! I’m glad to have gotten the propane friendly model, as I think some versions didn’t have it and I didn’t know enough to ask before purchase.

guzz3601 · 06-30-2021, 04:26 PM

On my 2021 2306BHS the 120 volt plug wasn't plugged in either. my water heater does the same thing. my dealer didn't have a clue to to adjust the flame. what i did was put a hose clamp on the burner tube and adjusted it that way. i don't know why the new water heaters don't have a flame adjustment like the old ones.

backtrack15 · 06-30-2021, 04:34 PM

Quote:

Originally Posted by guzz3601

On my 2021 2306BHS the 120 volt plug wasn't plugged in either. my water heater does the same thing. my dealer didn't have a clue to to adjust the flame. what i did was put a hose clamp on the burner tube and adjusted it that way. i don't know why the new water heaters don't have a flame adjustment like the old ones.

I was pondering how to make my own adjustment sleeve. I like the hose clamp idea. Seems perfect. Thank you.