Installing Tankless WH w/dedicated electrical Power

Maybe current model dual heat are a problem?

Jose

Old-Biscuit wrote:

NOTE:
In Photo connecting wire between Hi/Normal t-stats is burnt into on left set (120V AC) causing due to shorted electric element (high amp draw)

I guess you take your fuses where you find them :)

We have installed 3 tankless electric water heaters in 3 locations. They work great at the kitchen sink and to the dishwasher. Also good for supplying hot water to a nearby 1/2 bath sink in another location. Have used it in a small cabin for both the kitchen and bath sink as well as a shower in the bath. The sinks work fine but adding the shower was a bit of a stretch. It works but not as consistently as hoped.
Having said that they draw what I would think is too much wattage for an RV. Just use your Gas water heater. We use the electric heater during the day for sink etc, but when we plan on a nice long shower we flip the gas WH switch about 30 minutes before and have plenty of water.

westend wrote:
Thank you, OB.

What I was asking is if airtrooper had measured the DC voltage at the circuit board/controller to make certain he had good voltage. It may be that there is an issue with low/no voltage that is causing his problems.

Easiest place to check voltage (120AC or 12V DC) on Suburban WH is at t-stats.

Remove rubber cover and there they are.
Left side-120V AC==========Right side 12V DC
Top is High temp resettable t-stat. Power comes in to HI t-stat then to Normal t-stat.
120V AC then goes to electric element & 12V DC goes to control module


NOTE:
In Photo connecting wire between Hi/Normal t-stats is burnt into on left set (120V AC) causing due to shorted electric element (high amp draw)

Thank you, OB.

What I was asking is if airtrooper had measured the DC voltage at the circuit board/controller to make certain he had good voltage. It may be that there is an issue with low/no voltage that is causing his problems.

airtrooper wrote:
120 volts

120V AC doesn't go to circuit board.
120V AC goes from AC circuit breaker to AC Junction Box on side of tank then to ON/OFF switch in outside compartment (thru one inside rv IF you have one) to 120V AC set of t-stats to the electric element.

12V DC goes from DC Dist Panel Fuse to On/Off switch/light panel to DC Junction Box on side of tank to 12V DC set of t-stats to control module for ignition spark/gas valve

No electric.....check element. Probably burnt out if turned on w/o water in tank.
Otherwise check for tripped Hi t-stat (LEFT Push to Reset rubber cover in outside compartment) If not tripped....then pull cover and check t-stats.

No propane.....check tripped H t-stat (RIGHT Push to Reset)
Check for bad t-stats

120 volts

So what is the voltage at the circuit board?

Water heater is actually brand new - never worked properly last year when it was installed - the old one had similar issues - it was exactly the same model as I took out (tank was ruptured) - hooked every thing back exactly the same way - took pictures and marked wires & connections before I took the old one out, so I could make sure everything was connected the same; as you say it is not rocket science

airtrooper wrote:
I have a Suburban SW6DEM Gas Electric Water Heater with Motor Aided Spark Ignition - 6 Gallon - I push a switch in the (ROO 25S - 2005) camper and it is supposed to come on - most of the time nothing happens. Children have the camper out camping right now; daughter just heats water on the stove to wash dishes; they use the showers at the campground, but I just hate when things don't work the way they should.

Unfortunately, some things that are supposed to operate with the flick of a switch or the press of a button, sometimes don't. RV's, since the various systems are small, seem prone to this.

The best thing you can do for your water heater is inspect it and clean it with compressed air at least once a year. That will usually rid it of dirt and spider webs from storage. Removing rust is also a good maintenance item.

Before you try to ignite the heater, turn on the stove burners so that the propane line has a chance to fill with fuel and then try the ignite button. It may fail a couple of times before ignition, as the air is pushed out of the heater's supply piping.

You also may have a poor ignition scenario, orifice too far rom ignitor, ignitor not positioned correctly, lack of power to ignitor, etc. Those should all be checked out.

Before installing a separate demand system, I'd look at all of the above. Your demand system may have more bugs than the present tank system or may not work as foolproof as you estimate. It will also be costly to have it installed.

I'm sure you don't buy a new truck because the interior light doesn't work and it is the same with the heater. Do some maintenance and it should perform up to your expectations.