Help Seneca 37ts Truma

loki805 · 10-06-2018, 01:34 PM

Does the truma have a water heater bypass valve. If so does anyone know where it is

Rice1951 · 10-06-2018, 09:37 PM

I had the Girard tankless hot water heater swapped out for the Truma Comfort model back in June at Jayco Motorized so this will be the first time I have winterized it. I looked at the back of the unit which is accessible from inside the coach and there is no bypass kit installed. I would venture a guess that yours was probably installed without a bypass system also. That is a definite bummer because I dug out my manual and from what I read the Truma needs to be bypassed before introducing antifreeze into the system. I also went online and saw a couple YouTube videos indicating the same thing. So I will be installing a bypass kit next week after I return home from my current outing. And even though I can’t help you out thanks for posting the question because I now know I have more to do before winterizing and putting the coach in storage.

loki805 · 10-07-2018, 01:07 PM

Unfortunately there is no way to access the back of mine without taking it completely out of the camper. Even worse reading the owners manual made it sound like if I put all the valves in the wet bay in winterize it would bypass the heater. Unfortunately not it ran antifreeze through my heater which I immediately drained and rinsed so hopefully it didn’t screw anything up. Guess I’ll find out in spring. Have know idea how i’m going to get in there to put in a bypass before next year.

RVermont · 10-07-2018, 02:31 PM

On the 2018 seneca. The four control valves have a set point that bypasses the heater. All four valves are set side ways. This allows water to bypass the heater.

I also installed two valves in the wet bay so I can shut the heater off and drain the heater during freezing weather. This required no access to other bays. I simply cut the line and installed the valves in this bay. This allowed me to drive the unit in freezing weather with out having winterize the unit. Last fall I then upgraded the truma to the comfort model and bought the electric heater kit that keeps the unit from freezing.

To test if the heater is bypassed. Set the valves sideways, open the heater drain valve. Nothing should come out.

SloPoke · 10-07-2018, 03:09 PM

Glad we use compressed air instead. The only place we put antifreeze is in the drain traps.

loki805 · 10-07-2018, 05:27 PM

Quote:

Originally Posted by RVermont

On the 2018 seneca. The four control valves have a set point that bypasses the heater. All four valves are set side ways. This allows water to bypass the heater.

I also installed two valves in the wet bay so I can shut the heater off and drain the heater during freezing weather. This required no access to other bays. I simply cut the line and installed the valves in this bay. This allowed me to drive the unit in freezing weather with out having winterize the unit. Last fall I then upgraded the truma to the comfort model and bought the electric heater kit that keeps the unit from freezing.

To test if the heater is bypassed. Set the valves sideways, open the heater drain valve. Nothing should come out.

I tried the valves sideways according to the diagram still sent antifreeze to the heater

Rice1951 · 10-07-2018, 07:05 PM

Call Jayco Motorized. If your dealer did not or could not cover the winterization procedure then Jayco owes you an explanation. Good luck.

tallcott · 10-07-2018, 07:05 PM

RVermont: Last fall I then upgraded the truma to the comfort model

before you changed to the truma comfort, how did you do the decalcification to the unit?

RVermont · 10-08-2018, 01:42 AM

I only had the unit over the summer before I changed to the comfort model. I did not do a decalcification during that period. I just did a decal on the comfort model last long and it was very simple. The process for the basic appears to require a special tool that replaces the screen during the process. This tool is basically a device that allows a solution of acid to be circulated through the heater for an hour or so. There is a video of the process though I don’t recall where I found it.

Mnwelsh · 10-08-2018, 07:48 AM

I had a Truma installed 18 months ago. They installed 3 water heater bypass valves behind the heater. There us an access panel they made in the side if the hot water heater compartment. It is reachable by opening the door to the generator compartment.

RVermont · 10-08-2018, 09:16 AM

Quote:

Originally Posted by loki805

I tried the valves sideways according to the diagram still sent antifreeze to the heater

I went and looked at my unit again and this is how it appears to work.

The red knob directs the cold water into the heater, but it doesnt look like there is anything on the hot water side. So with the system full of water turning the red valve sideway stops the flow into the heater, you can then run antifreeze through all of the fittings in your unit, both hot and cold. Since the cold supply to the heater is off there should be no way for the antifreeze to get into the heater. Once you have flushed everything through you can drain your lines via low point drain and then finally drain your hot water heater. While this appears to be the case, I would still think a ball valve on the hot water discharge side of the unit would make this a simpler process.

If you drain your hot water tank or open the low point drain at the heater you will allow antifreeze to back flow into the heater through the hot water lines.

Having said all this, the Nautilus manual expressly says to drain the system prior to introducing the antifreeze, if you do this there doesn't appear to be anything to prevent the solution from flowing backwards into the heater unless the heater has some sort of backflow prevention.

I tested the theory that the cold water was back flowing by shutting off the valve I installed on the hot water discharge line and the put the red valve sideways, this allow me to drain the heater.

The quickest way to resolve this is to install a ball valve on the red hot water line behind the nautilus system. That way you can fully drain the system, close the valve and turn the red on sideways and you will be good to go.

RVermont · 10-08-2018, 10:16 AM

Here is a rough drawing of how the flow appears to be with the Nautilus p3 panel in seneca's from 2018.

loki805 · 10-09-2018, 04:36 AM

Quote:

Originally Posted by RVermont

Here is a rough drawing of how the flow appears to be with the Nautilus p3 panel in seneca's from 2018.

Thanks for your research. I have it winterized for this year I hope running antifreeze through the heater didn’t hurt anything. I tried to rinse it out the best I could. Why would antifreeze be so bad for it anyways?

Crossingover · 10-09-2018, 06:01 AM

Quote:

Originally Posted by loki805

Why would antifreeze be so bad for it anyways?

I don't think it is 'bad' for the water heater, just that it would take 6 gallons or so of the pink 35/65 food grade propylene glycol/water mix (and wasted $$$) to fill a standard water heater, which is why most RVs have a water heater bypass for winterization. I think that logic mistakenly migrated over with the on-demand water heaters that have a much smaller water volume. I'm in the blow the lines out with compressed air/pink stuff in the drain traps camp anyway.

Rice1951 · 10-14-2018, 08:05 AM

Quote:

Originally Posted by loki805

Thanks for your research. I have it winterized for this year I hope running antifreeze through the heater didn’t hurt anything. I tried to rinse it out the best I could. Why would antifreeze be so bad for it anyways?

So after following this thread I decided to call Truma and get their opinion. Their customer service rep stated Truma’s official recommendation is to bypass the heater. The reason for this is that it is possible a manufacturer could introduce chemicals into their RV antifreeze product that could be harmful to parts of the Truma system. Under most circumstances it would be fine but since Truma has no control over what a consumer might introduce to the water system they officially recommend bypassing it.

loki805 · 10-16-2018, 08:14 AM

Quote:

Originally Posted by Rice1951

So after following this thread I decided to call Truma and get their opinion. Their customer service rep stated Truma’s official recommendation is to bypass the heater. The reason for this is that it is possible a manufacturer could introduce chemicals into their RV antifreeze product that could be harmful to parts of the Truma system. Under most circumstances it would be fine but since Truma has no control over what a consumer might introduce to the water system they officially recommend bypassing it.

Good to know, thanks for the leg work.

McGintys924 · 10-20-2018, 06:40 AM

Quote:

Originally Posted by tallcott

RVermont: Last fall I then upgraded the truma to the comfort model

before you changed to the truma comfort, how did you do the decalcification to the unit?

According to Truma there is no way to diy the decalcification process without the upgrade (one of the many complaints that Jayco used the basic). There must be some dealer only components they use for those with basic.

McGintys924 · 10-20-2018, 06:44 AM

Quote:

Originally Posted by RVermont

On the 2018 seneca. The four control valves have a set point that bypasses the heater. All four valves are set side ways. This allows water to bypass the heater.

I also installed two valves in the wet bay so I can shut the heater off and drain the heater during freezing weather. This required no access to other bays. I simply cut the line and installed the valves in this bay. This allowed me to drive the unit in freezing weather with out having winterize the unit. Last fall I then upgraded the truma to the comfort model and bought the electric heater kit that keeps the unit from freezing.

To test if the heater is bypassed. Set the valves sideways, open the heater drain valve. Nothing should come out.

Could you send a picture of how you did this? This may give me an option to still have some water when temps get super cold; comfort burns a lot of LP at cold temps. Tomorrow I am going to follow your pictures on how you did the water tank boards.

You may also like: