Instant water heaters, Pros and Cons

[grantgoold]

Folks, I am looking for some real world experience with instant water heaters for the bus. I have seen LP, and Electric designed for marine and rv. I have also seen the instant heater that is the complete shower head with electrical cord. What have you experienced?

Thanks

Grant

[Nick Badame Refrig/ACC]

Hi Grant,

Electric POS heaters use quite a bit of current. Other then that, they would be a good unit for your bus.

LP units, need to be direct vented. They also need combustion air to work properly. It's alyways been a challange

to install one in your bay because of the above reasons. I don't use LP onboard, otherwise I might concider one.

Good Luck
Nick-

[Greg Roberts]

Although a bit pricey, I am considering installing the RV 500 http://www.coolrvtoyz.com/content/rv-500-direct-replacement-rv-tankless-water-heater into my bus. I current have a marine unit with an exchanger but I believe a gas unit will give me a much better boondocking ability now that I am starting to change the way we use the bus (more sitting in unimproved locations and less rolling). This unit makes sense because it is a direct vent and designed for RV use. I am still considering a regular tank type propane unit too as a second choice. - Greg

[Lin]

We had a Poloma in our last bus.  I thought it was great.  The flow is lower but was adequate.  I currently have a 10 gallon electric, but would look to the instant type if this one failed.  One thing that I will mention though is that the Poloma in that bus was just installed in the bathroom on the wall.  It was not vented.  It was like that when we got the coach.  I considered venting it at first, but it never presented any problem.  For normal, on/off use, the amount of exhaust produced was minimal.  The unit was near the bathroom roof vent, which could be opened a little if you were taking a long shower.  When you come down to it, it produced less exhaust than cooking dinner and never set off any alarm.  I believe this could be controversial, but it did work.

[Nick Badame Refrig/ACC]

We had a Poloma in our last bus.  I thought it was great.  The flow is lower but was adequate.  I currently have a 10 gallon electric, but would look to the instant type if this one failed.  One thing that I will mention though is that the Poloma in that bus was just installed in the bathroom on the wall.  It was not vented.  It was like that when we got the coach.  I considered venting it at first, but it never presented any problem.  For normal, on/off use, the amount of exhaust produced was minimal.  The unit was near the bathroom roof vent, which could be opened a little if you were taking a long shower.  When you come down to it, it produced less exhaust than cooking dinner and never set off any alarm.  I believe this could be controversial, but it did work.

Hi Lin,
Not only should they be vented... but, they are not recommended for manufactored housing/RV's. They do get very hot!
http://www.besthotwaterheaters.com/data/filestorage/manuals/paloma-waiwela/ph-20r-manual.pdf

Last friday night, I recieved a service call from a new customer who was complaining of a smell they thought was from their
heater. They wanted to wait until Monday because they didn't want to incurr overtime rates. I told them to not worry about
the OT rate and I would be there in an hour. When I arrived at their door, I knocked and noticed the fellow just standing about
5 ft from the door but, he was not letting me in. I then pushed the door open to have a wall of carbon Monoxide hit me in the face.
I pulled the fellow and his wife out the door for fresh air. It took them about 20 min's to get their senses together... I inspected
their heater only to find no CO's comming from that. As I walked into their den, I then found a ventless gas log set burning away.
My $1200 CO detector went full tilt. The log set was about 15 years old and was never serviced! I fornd clogged orfices,
and a build up of carbon on the logs. What were they thinking!! It was very cold out but, that's no reason to kill yourselves....
I tried to convince the customers to get checked out at the hospitol but, they refused..

Please dont mess with Carbon Monoxide... It's deadly to say the least!

Nick-

[Len Silva]

Nick,

Not only is CO a deadly poison, it is cumulative.  Multiple exposures over time can be toxic.

From Iowa State University:
http://www.extension.iastate.edu/pages/communications/CO/co_cases.html

Carbon monoxide symptoms mimic other medical conditions such as the flu, heart attack and muscular sclerosis. Carbon monoxide kills by replacing oxygen in the blood. High levels kill in a short period. Moderate levels, because CO is a cumulative poison, can cause misdiagnosed health problems or even death. Low levels over a long period can cause health problems, especially for patients at risk. Exposure can result in long lasting or permanent effects including brain damage. After exposure, merely removing the victims from the area is not enough. Some form of medical attention is required. The most effective treatment uses a hyperbaric chamber, where, under pressure, the CO is quickly replaced with oxygen.

[JohnEd]

In my first Psychology course the prof related a case of poison altering behavior in the Physio Psyc portion.  The poison was CO.  Seems a family in NY City was experiencing sever headaches...mom, dad and two kids.  Emergency room could find nothing but kept mom for observation as she was incapacitated.  She recovered after a few days  and went home but without any diagnosis.  Another anomaly was that dad got the headache on Sunday but it went away by Monday afternoon and he had no problems till Sat afternoon.  They bounced in and out of ER for a month.  Then Mom KILLED both kids and went for Dad with the knife when he got home from work.  Final finding was that CO from a clogged hot water heater vent (birds nest) was the problem.  Prolonged exposure to low levels of CO will give you a severe headache and/or make you behave violently.

Nick,

Those people obviously owe you their lives.  They should thank God you are the man you are.

Sincerely,

John

[HB of CJ]

My apartment has two (2) instant electric hot water heaters, one in the bath, the other in the kitchen.  Great gadgets.  Mount under the sink.  Looks retro, but work fine.  The kitchen one is set high sooss you can brew hot tea/coffee.

Neat to have instant hot water when you turn on the tap.  No waiting 3 minutes.  Can take endless showers (have) and still have hot, hot water.  No need to be vented exactly like LP or NG instant water heaters.  Simple installation.

In a Bus Conversion, a large Invertor(s) will be needed.  Electric hot water heaters are real energy hogs, especially the 110 vac versions.  Mine are 220, which would be difficult in a coach.  Light weight, simple, NO big venting required.

Consider it like an electric coffee maker, dry popcorn machine, microwave or the electric cook top elements.  Great Hoggs when you use them, but you only use them a short period of time.  Great for all electric Bus Conversions.  HB of CJ 

[Lin]

Nick and others,

As mentioned, the bus had the Poloma when I got it.  I soon found that it was not recommended for RV use, which I assumed was due to it not being designed to hold up to vibration.  However, it worked perfectly for about 10 years.  We never noticed any problem with heat from the unit.  However there was a sheet metal deflector above it that probably cooled the exhaust a bit and directed it toward the roof vent.  I would not tell someone to install one without venting, but was relating that this one seemed to vent enough by merely opening the roof vent.  The CO alarm never sounded.  Anytime we cook with gas/propane, we are adding CO to our atmosphere although, as I understand it, the less yellow in the flame, the better.  That is partially how they get away with allowing unvented heaters in many states  (which, as your experience shows, are to be watched very carefully if you have one).  In any case, we no longer own that bus.

[John316]

Okay, guys. What is the difference between these instant hot water heaters, and a diesel fired Aqua Hot or Oasis. We haven't put our hot water system in yet, so I was wondering. I don't think that we would do an instant electric hot water heater, but we might (and we also have the power needed with two four thousand watt Xantrax inverters).

So my question is. Why go with electric (propane isn't an option since we won't have it anyways). Is it price? Better heating? Cleaner? I just wondered if you all had some insight on this.

God bless,

John

[Nick Badame Refrig/ACC]

Nick and others,

As mentioned, the bus had the Poloma when I got it.  I soon found that it was not recommended for RV use, which I assumed was due to it not being designed to hold up to vibration.  However, it worked perfectly for about 10 years.  We never noticed any problem with heat from the unit.  However there was a sheet metal deflector above it that probably cooled the exhaust a bit and directed it toward the roof vent.  I would not tell someone to install one without venting, but was relating that this one seemed to vent enough by merely opening the roof vent.  The CO alarm never sounded.  Anytime we cook with gas/propane, we are adding CO to our atmosphere although, as I understand it, the less yellow in the flame, the better.  That is partially how they get away with allowing unvented heaters in many states  (which, as your experience shows, are to be watched very carefully if you have one).  In any case, we no longer own that bus.

Hi Lin,

Yes, yellow flame shows us that there is incomplete burn. In other words, lots of CO and fuel particulates escaping unburned.
Blue Flame is what is used in ventless heaters because it's much hotter and Almost completely burns all the fuel and CO's. What
is mostly left over is H20 in the form of humidity. Notice I said Almost...
Any appliance used in an unvented area such as a home should be equiped with an [ODS], oxygen depletion sensor and in most
states , also a [CMS] carbon Monoxide sensor. Both integrated into the safty shut down feature. Just about every set of instructions
that I have read have always stated that when such apliances are used, a window should be cracked as well as Never use while
sleeping.

Nick-

[Nick Badame Refrig/ACC]

Okay, guys. What is the difference between these instant hot water heaters, and a diesel fired Aqua Hot or Oasis. We haven't put our hot water system in yet, so I was wondering. I don't think that we would do an instant electric hot water heater, but we might (and we also have the power needed with two four thousand watt Xantrax inverters).

So my question is. Why go with electric (propane isn't an option since we won't have it anyways). Is it price? Better heating? Cleaner? I just wondered if you all had some insight on this.

God bless,

John

Hi John,

What ever you choose, think redundency! Always have a back-up system. They only break when you need them the most.
Heaters don't break in the summer and A/C's don't break in the winter...LOL
I have 2 heat pumps as well as a diesel Proheat system with a hydronic coil tyed into the duct work.

Good Luck
Nick-

[Fred Mc]

I have had a Paloma LP heater in my bus for about 20 years. It is mounted in a bay and vented through a loovered vent in the bay door. It has worked well, once I figured out how to use it.

The unit comes on when the water pressure drops and stops when the pressure builds up. This can cause a problem when trying to use it with a water saving shower head. Because it causes a restriction of flow it tricks the heater into thinking the pressure has built up and the heater shuts foo. Poof, cold water in the shower, so you adjust the tap for warmer water and it goes to hot and so on. This was solved by taking the water saver feature out of the shower head.

As long as you have water and propane you can have hot water. And the unit saves space.

Fred M.

[TomCat]

The PrecisionTemp RV500 doesn't have the above problems...it has a flowmeter to control the burner when the flow changes.

I have used one for 4 years, and feel it is worth every cent it cost.

Jay
98 SaftLiner

[TomC]

I know I've posted this before, but please consider a simple water heating system.  I believe I have that- 2-10gal elec water heaters bought straight from Home Depot for less then $400.00.  One is plumbed into the next for 20 gal effective hot water, and the final water heater is wired through the inverter for hot water during the day driving down the road.  No Diesel fumes or fuel lines, no igniter, no water pumps, no coolant lines, no heat exchangers-just simple, silent hot water that's 100% reliable over the past 14 years being in my bus.  Just have to run the generator in the morning to warm the water for showers (when dry camping)-have to do that anyway to charge the batteries (I have a compressor type 12v/120v Norcold refer).  Takes about 45 minutes to warm from cold.  Like the system so much, will use it in my next conversion.  Good Luck, TomC