Ram Promaster Forum banner

101 - 120 of 121 Posts

·
Registered
Joined
·
91 Posts
What is the downside to just letting the tank get to max temperature? That is what it is designed for. The mixer value on the output should keep the tap water at the right temperature.
There's probably nothing wrong with just letting the coolant circulate. The tech help lady at Atwood confirmed this for me a while ago. She said, like you said, it is designed for that kind of usage.

On the other hand, many times I don't want to heat water. Maybe I haven't filled the water system or maybe I'm just using the van for whatever. I found, with other motorhomes I've had, that heating water and not using it makes for stinky water. I have ball valves to turn off the flow but it would be cool to control that from inside.
 

·
Registered
Joined
·
168 Posts
Discussion Starter #102
What is the downside to just letting the tank get to max temperature? That is what it is designed for. The mixer value on the output should keep the tap water at the right temperature.
The main downside I see is that in hot weather it is putting a lot more heat into the interior than is needed for usable hot water. I have several micro-controllers for my solar thermal system and setting them up is really quite simple. They just open or close contacts based on input from a thermocouple at a selectable temperature. The main thing is to find a valve that will meet the parameters of our hot water systems.
 
  • Like
Reactions: bahawton

·
Registered
Joined
·
1,380 Posts
Just finished tapping into the heater hoses above the engine. 3/4"x3/4'x3/4" brass tees worked just fine for the splices. To make more space for the tee-splices, I ended up cutting the existing heater hoses flush with the ends of heater core nipples and cut off the hose remaining on the them. I bought one foot of 3/4" silicone heater hose and cut 2+" lengths for two of the three nipples on each tee, one to the heater core and the other to a 3/4' barbed nipple screwed into a 1/2" ball valve on each new hose line. I will be running 5/8" hose back to the HWH, so I screwed 5/8" barbed nipples into the other end of the ball valves.

It turns out the upper (return) heater core nipple is 5/8" and the lower is 3/4". The factory hoses appear to both be 3/4". I had some 5/8" silicone, so I used that on the upper instead. I figured a tight fit on the tee was better than a loose fit on the core.

I caught most of the anti-freeze that spilled. Getting it back in and removing the trapped air was the trick. The air was all nicely concentrated at the top of the coolant system, so I didn't want to start the engine and circulate it. Instead, I added a temporary short piece of heater hose to the ball valve on the supply-side, bent it upward until it was the higher than the rest of the system, stuck in a funnel and opened that ball valve. Then I opened the bleed screw on the elbow of the return hose and VERY SLOWLY poured anti-freeze in the funnel until it came out the bleed screw. Then I closed the bleed screw and ball valve. That removed most of the trapped air, the rest can work itself out. I zip-tied the ball valve handles closed just to be safe before I started and drove the van again. I'll report back again after I add the long hoses back to the HWH.
I am happy to report this part was much easier than I expected.
BTW, I got the brass tees and brass barbed nipples from Amazon.com. I also got gear-clamps with solid inside collars. Teflon tape over pipe dope on all the threaded brass connections. The factory hose clamps on the heater core come off (too) easy. Just insert a screwdriver under the big arch and pry up.
 

·
Registered
Joined
·
870 Posts
I just did my tie in this weekend with the factory "kit". I found that the vertical two coolant lines are not the same size. In all of my "cleaning up" in the garage I lost the larger clamps from the kit, so I had to go to NAPA for those. Nothing fancy, just regular hose clamps.

I prefilled the new lines before connecting them. Loctite 592 for the couple of brass threaded connections. Ball valves on both ends of each line.

I'm with SteveSS, this was pretty easy once I worked up the courage to cut into the coolant lines.
 

·
Registered
Joined
·
509 Posts
I may have run into a snag with the Isotemp. My desired location is on top of the wheel well. This puts the Isotemp coolant loop above the engines expansion tank.

I think I need to install a new expansion tank above the Isotemp. Thoughts?
 

·
Premium Member
Joined
·
8,649 Posts

·
Registered
Joined
·
84 Posts
Getting ready for this probably easy but nervwracking project! I am assuming that it will be similar to when I cut in the roof vent and three windows a few months ago! I was anxious to do it, but now I don't even think about those holes! Has anyone tried the Gates PowerGrip heat shrink clamps? I watched the few videos that I could find but they were all from 5-7 years ago. I was considering using them on all of the connections. Supposed to be awesome, but seems not a lot of people have tried them?
 

·
Registered
Joined
·
509 Posts
I think I updated my other thread but lets do it here also.

No expansion tank was needed.

Installed shut off valves with air bleeders. That was totally unneeded and it is just another failure point.

As per another member's idea...

The final connection sequence went like this...

The isotemps output hose was left open in the engine bay. The van was started. The rpm was held around 1500 rpm. When coolant came out I made the final connection. A little messy but no air bubbles.

I am getting some dribbling out a hose. Might need to switch to constant tension hose clamps.
 

·
Registered
Joined
·
2,206 Posts
Sitting here taking a lunch break and browsing, looking at how people are heating their water.
I had an idea and grabbed a piece of paper and scribbled it down before I forget.
What if it was piped like this, which is essentially the way it's being done with the shut off valves, only adding a 3rd valve and a few options.
You could partially close the valves going to the water heater (V2 and V3), to keep it from getting full flow and heat transfer, while leaving V1 open.
You could close V1 and fully open V2 and V3 for quickly heating the water.
Or you could close V2 and V3 and not exchange any heat at all to the house water and the cooling system would operate normally. Off the top of my head, the biggest issue would be convenience and valve location/accessibility.
Any thoughts?
 

Attachments

·
Registered
Joined
·
2,206 Posts
I suppose, just like wiring a light switch, you could reroute the lines and place the valving in any location.
The key would be to have it all inline, off either the send or return line.
 

·
Registered
Joined
·
870 Posts
For my setup and my weather, there is no reason to install your V1. The van will heat the water thank in about 30 minutes from 50F ambient. If the water isn't hot enough, i just hit the electrical heater for 20 minutes. I have ball valves at both ends of both lines. It was cheap and easy to do during the install.
 

·
Registered
Joined
·
2,206 Posts
Did you put the valves inside the van or out?
I'm curious if anyone has tried putting them inside for easy access.
I assume most folks just tie in under the hood at the firewall and just let the coolant circulate though the water heater year round (with no issues or need to access?)
 

·
Registered
Joined
·
168 Posts
Discussion Starter #114
Did you put the valves inside the van or out?
I'm curious if anyone has tried putting them inside for easy access.
I assume most folks just tie in under the hood at the firewall and just let the coolant circulate though the water heater year round (with no issues or need to access?)
I have ball valves at the firewall but also inside the van near the HWH. On a recent three week trip to CO I used the engine connections to get the Isotemp 40L HWH up to around 160F then shut off the valves. When camping (no hookups) I found it more convenient to plug in the HWH around 10am when the batteries were fully charged. It took an hour or two to bring up the temp to about 138F which appears to be the factory setting for the resistance heat element. Or maybe that can be adjusted but in any case it is a satisfactory temp for my use. My 654watt solar array can just about keep up with the HWH draw current on a sunny day. Right now I just manually plug in the HWH but I'm going to put in a switch to make it more convenient. In hindsight perhaps I shouldn't have bothered making the engine connections while having a large solar array. With connection of my 220amp alternator to house batteries I can easily keep the HWH up to temp with the 110v element while driving as my 2kw inverter already runs 24/7 for the compressor fridge.
 

·
Registered
Joined
·
870 Posts
Like wbullivant, my engine side valves are right at the point where I tapped into the coolant lines. The other end valves are in the cabinet with the WH. I put int eh extra just in case I needed to do some work and I didn't want to spill coolant everywhere.
 

·
Registered
Joined
·
2 Posts
Nice to hear from someone with first hand experience with an Isotherm and engine cooling connection. Do you have any idea how hot your tank got? My only concern is that it will get considerably over the recommended 200F maximum temperature if there is no system to control the hot coolant. But I certainly agree you want it up in that area for maximum hot water capacity and in my case btu storage for space heating. I bought the rear heat option when I ordered the van. There may be some stuff I don't know about (possibly rear AC prep) but it looks I paid $90 or so for $10 worth of fittings. Two 1/2" x 3/8" Tees and clamps which I'm sure you can buy. The ones Ram supplied are plastic, probably with fiber reinforcement, but I'm sure brass would work just fine. I used 1/2" stainless Pex clamps on the 3/8" silicone radiator hose and they are perfect for the application. Worm gear clamps in small sizes don't clamp evenly. Bill
So excuse my ignorance but here goes....I am to understand that you have tapped into the engine glycol/cooling system. Does Promaster approve of this regarding any warranty issue? Has anyone actually installed an independent glycol loop system going to the engine and then back to the water heater? If so, please provide detail. Thanks.
 

·
Registered
Joined
·
870 Posts
So excuse my ignorance but here goes....I am to understand that you have tapped into the engine glycol/cooling system. Does Promaster approve of this regarding any warranty issue? Has anyone actually installed an independent glycol loop system going to the engine and then back to the water heater? If so, please provide detail. Thanks.
Yes, this system taps into the engine's coolant lines. I used the factory kit to do it, so I doubt they can complain about it.
 

·
Registered
Joined
·
215 Posts
So excuse my ignorance but here goes....I am to understand that you have tapped into the engine glycol/cooling system. Does Promaster approve of this regarding any warranty issue? Has anyone actually installed an independent glycol loop system going to the engine and then back to the water heater? If so, please provide detail. Thanks.
As noted above, the plumbing pieces needed to connect to the engine cooling system were available as an option from Promaster. They consist of 2 'tees' and 6 hose clamps. My Promaster didn't come with the option so I bought the parts from NAPA.

Because of the heat, use high quality fiberglass reinforced plastic tees or metal ones. I started with some inexpensive tees labeled as Ford heater parts and they were weakened by the heat. I changed to the fiberglass reinforced type and they have been in place for 6+ years.

They are inserted in the 2 coolant hoses coming out of the top of the firewall that connect to the cab heater core. I asked the service manager at my Promaster dealer if I should drain the coolant system a little before installing them to minimize coolant loss and he told me not to bother. When they install them they just cut one hose at a time, insert the tee and add a little coolant to make up for the small quantity lost.

Certainly that was their opportunity to tell me about any warranty issues.

When I inserted each tee I already had a short piece of hose with a ball valve connected to the tee with the valve closed so there was minimum coolant loss. Later I connected the hoses going to the back of van where I have the Isotherm heater mounted. The ball valves make it possible to isolate the cooling system if there is a problem with the heater or I need change something.

You have to add additional coolant to allow for the volume of the hoses and heat exchanger inside the heater and you have to bleed the air from the new hoses. There is a bleeder on one of the hoses coming out of the firewall, but I didn't know how it worked so I just loosened the clamp on the tee connected to that hose and ran the engine until coolant had gone to the Isotherm and began to run out. Any residual air will work it self out by driving and checking the coolant level. Some people prefill the hoses running back to the Isotherm to make the bleeding step easier. Make sure you mount the Isotherm below the connection to the engine coolant hoses so they are the highest point in the system.

Isotherm calls for 1/2 inch hoses, but as noted above 3/8 inch works fine. Our 4 gallon tank heats quickly while we drive, because of the mixing valve that mixes the 190+ degree water with cold water, provides 2 'navy' showers and dish washing after parking for up to 2 days and if parked longer, heats up by idling 10 - 15 minutes. In a previous conversion, a 6 gallon version would last up to 3 days without driving.

If you do connect up the electric element for heating on shore power be advised as Hein discovered, the coolant temperature will trip the over temp thermostat and the electric element won't work until you remove the front cover and press the red reset button. I drilled a small hole in the cover above the reset button and I can reset it with a small dowel.

Engine heated hot water heaters have been used for decades on boats and many RVs. I've used this system on 3 camper conversions and 2 sailboats over the last 40 years. I understand the concerns of people unfamiliar with it's use, but if you use quality components like the Isotherm with its stainless steel tank and its temperature regulating valve there's no need to be concerned with it's safety.
 

·
Registered
Joined
·
1,380 Posts
What @tgregg said. We love ours. We could have got by with the 4gal IsoTemp instead of 6.5gal, but we got it on sale ;) I used brass tees, 5/8" hose, and ball valves at both ends. Just to be safe, we don't drink from the fresh water system connected to the IsoTemp. Never heard of one leaking toxic coolant into a fresh water system, but better safe than sorry.
 
101 - 120 of 121 Posts
Top