Community Forums

Red N Susan · 08-23-2014, 04:41 PM

We are looking at purchasing our first MH (possibly a Winnebago Vista which does not come with a tankless hot water system, only a 10 gallon hot water heater). We are interested in opinions on the Precision RV-550.
We are considering doing the installation ourselves. If not, does anyone know of a reputable RV service company in the Houston, Tx. area?

**CLIFFTALL** · 08-23-2014, 04:44 PM

Welcome to irv2. I've moved your post here to get a broader view.
Cliff

MSHappyCampers · 08-23-2014, 05:26 PM

Hi folks! Welcome to IRV2! We're sure glad you joined us!

Hope you find the right rig for your needs! Enjoy the forum!

Good luck, happy trails, and God bless!

GunnyClark · 08-23-2014, 05:36 PM

Welcome to IRV2!!!

the wife and I have also talked about getting a tankless system but have not done very much research on it until I do a couple of other mods. Let us know how it turns out for you if you get a system

wa8yxm · 08-23-2014, 05:46 PM

Ok tanked v/s tankless... With a tanked system you have hot water at all flow rates, and you can often use either gas or electric heat.. If you are in a park, as I am, where the electricity is included in the flat rate rental.. That's the way to heat water (On a metered site use gas).

Tankless at very low flow rates you may not trip the flow sensor (like the sail switch on the furnace if the flow is not good enough NO HEAT)

and they run on gas,, Running on on electric is theoretically possible but either only at very low flow rates or at very high power rates. The only one I have found that would fit inside my power consumption profile limits flow to like 1/4 Gallon per minute.. I need 1 GPM minimum to heat water for tomorrow's shower or.. My six gallon tank, either will work.

(Though the way the temps are today I am not sure I actually NEED to heat the water..... 100 in the shade, just leave the hose in the sun and ..)

**pasdad1** · 08-23-2014, 05:58 PM

Quote:

Originally Posted by Red N Susan

We are looking at purchasing our first MH (possibly a Winnebago Vista which does not come with a tankless hot water system, only a 10 gallon hot water heater). We are interested in opinions on the Precision RV-550.
We are considering doing the installation ourselves. If not, does anyone know of a reputable RV service company in the Houston, Tx. area?

Since you haven't bought an MH yet....why not look for ones with "aquahot" which is a tankless water heater and coach furnace all in one?

jspande · 08-23-2014, 06:02 PM

The Precision Temp is a good unit (perhaps the best tankless RV WH), but a tankless WH may be somewhat at odds with your RV lifestyle, depending on whether you almost always have city water connection or if you sometimes dry-camp.

They are not very compatible with water conservation, since they require a substantial minimum flow of water to prevent on-off cycling of the burner (and thus of water temp). I believe it's 0.4 gal/min and that assumes a reasonably cool source water temp - if the source water is fairly warm the minimum flow required goes up.

DieselTech39 · 08-23-2014, 07:36 PM

Glad you're aboard. Best of luck in your search and decision. Enjoy your adventures and be safe.

Sky_Boss · 08-23-2014, 08:26 PM

Quote:

Originally Posted by wa8yxm

...If you are in a park, as I am, where the electricity is included in the flat rate rental.. That's the way to heat water (On a metered site use gas)....

I don't want to spin this thread too far off but I suggest that, maybe, just maybe it is better to use electricity for water and general heating needs most of the time if electric is not included in the camping fee. It depends on the cost of electricity vs propane.

As an example, if electricity is $.12/kwh and propane is $3/gal and assuming the gas heating is only 60% efficient, the cost of 100,000 BTUs of heating is $3.52 for electricity and $5.42 for propane.

Comparison Calculator

No calculator is perfect. As an example, since heat pumps lose efficiency as temps drop, they may have to run longer than a gas furnace so that could skew the comparison a bit. It would also appear that electric heating is more cost effective than burning diesel for hydro heating systems too.

tricotec · 08-23-2014, 08:33 PM

Quote:

Originally Posted by Sky_Boss

I don't want to spin this thread too far off but I suggest that, maybe, just maybe it is better to use electricity for water and general heating needs most of the time if electric is not included in the camping fee. It depends on the cost of electricity vs propane.

As an example, if electricity is $.12/kwh and propane is $3/gal and assuming the gas heating is only 60% efficient, the cost of 100,000 BTUs of heating is $3.52 for electricity and $5.42 for propane.

Comparison Calculator

No calculator is perfect. As an example, since heat pumps lose efficiency as temps drop, they may have to run longer than a gas furnace so that could skew the comparison a bit. It would also appear that electric heating is more cost effective than burning diesel for hydro heating systems too.

The problem with using electricity for hot water tankless systems is that the amperage requirements to get satisfactory performance in an RV are too high. To match the BTU input of the Precision RV-550, you would need 28A of current at 110VAC!! More than most any production RV could handle! Most RV hot water systems including the aquahot and most propane/electric water heaters use a relatively small electric element to keep water hot during low use periods to save fuel. All of them consume fuel when you use hot water for anything more than washing your hands. To use tankless hotwater in an RV you'll need to either use propane or Diesel (in a DP rig) to get enough BTUs to heat enough water to take a shower. I highly recommend an aquahot system.

However the Precision RV-550 looks like it is specifically designed to replace a typical Suburban 6 gallon water heater. I can tell you that having unlimited hot water in an RV is WELL worth it and will improve your quality of life while in your RV. It's a must for full-timers. Keep in mind that you'll only benefit from these if you are in a park with an unlimited supply of water. If you camp in the wilderness you will quickly empty your fresh water tank if you indulge in long showers, and the small RV water heaters are fine for most "RV wet down and soap" showers. I'd love to hear from those who have one of these how well it works.

**Lt Dan** · 08-23-2014, 09:56 PM

Quote:

Originally Posted by Red N Susan

We are looking at purchasing our first MH (possibly a Winnebago Vista which does not come with a tankless hot water system, only a 10 gallon hot water heater). We are interested in opinions on the Precision RV-550.
We are considering doing the installation ourselves. If not, does anyone know of a reputable RV service company in the Houston, Tx. area?

Do your research. Some friends of ours had a brand new 5th wheel that came with a tankless heater. Their second trip it caught fire and caused a lot of damage. After the repairs, the company replaced it with a standard heater and said they had had problems with tankless RV heaters.

Just for info, we have a 10 gallon WH that works on gas and/or electric. You can turn on both gas and electric at the same time and the recovery rate is very fast. Unless you take 20 minute showers, a 10 gallon WH may be enough for you because the water is hotter than a regular residential WH.

Just my $0.02 worth.

Medico · 08-24-2014, 08:42 AM

Welcome and glad to meet you!

PyrateSilly · 08-24-2014, 09:28 AM

We have a 10 gallon water heater. I can do dishes, Thom can take a shower and then I can take one ..... all within about an hour. The 10 gallon tank works just fine and we usually keep it on electric. If power is lost we will turn it off but usually it stays on electric.
The shower does have a shut off valve so that during the shower when we are soaping up and stuff and don't really need the water to just run we can stop the flow without turning it off completely. It helps tremendously to have the shut off on the shower head, it cuts down on water just flowing no where and helps with us being to use just the 10 gallons of hot to take showers. The tank may say 10 gallons but if you use the shut off valve then while you are doing whatever the tank is heating more water so that you should then again have a full tank by the time you turn the valve back on. The only time I have come close to running out of hot water is when I decided to just stand under the water and let it flow.

When we did have a stick house we did put in an electric tankless water heater. They are more efficient than a gas one. http://www.energystar.gov/ia/partners/prod_development/new_specs/downloads/water_heaters/Eemax_052907.pdf
The one we got for the house was also rated for cold weather since it was in MI. It worked great but while Thom and I remembered that just because you have endless hot water does not mean you should use endless hot water .... costs more money for some people because they forget that the more you use the more you will pay.