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Floridastorm · 01-16-2023, 09:16 AM

Have watched a lot of You Tube Videos on various aspects of my motorhome as I am sorely inexperienced in RVsmenship. I have not found one video that adequately explains the workings of the water heater from A through Z.

Two situations:

Off grid with a full fresh water tank. My understanding is that the fresh water tank does not automatically fill the water heater. You open a tap until air is cleared out of the line and water is put into the water heater from the fresh water tank. How long does it take to fill the water heater? Then shut off the tap. Turn on the switch that starts the DSI and begins heating the water. Wait a few minutes until water is hot. Not sure how that is determined. Then open the tap for hot water. Where am I going wrong?

On grid hooked to the RV park water line. My understanding is that in this situation the water heater is automatically filled. After that the rest of the exercise is similar to the off grid scenario. Where am I going wrong?

Just want to make sure that I am not inadvertantly taking a chance on burning up my water heater and as such need to do it correctly from the get go.

You would never know that in my career I handled up to 9 figure engineering/construction contracts for multinationals and have to proceed with baby steps now.

deandec · 01-16-2023, 09:44 AM

I have a 28 year old Atwood 10 gallon water heater.

If I use our onboard water supply, I just turn on the water pump (unless it has been operating in the recent past so the water heater tank is full) before turning on the water heater. That has worked for 21 years with no bad results.

Same deal with shore water. Turn it on at the coach shore water entrance and then start the water heater.

I am not aware of a way to turn off the water flow to the water heater, but I have never needed that ability either.

Actually, I only drain the water heater tank water 1x per year to clear out the junk it accumulates.

Floridastorm · 01-16-2023, 10:22 AM

Quote:

Originally Posted by deandec

I have a 28 year old Atwood 10 gallon water heater.

If I use our onboard water supply, I just turn on the water pump (unless it has been operating in the recent past so the water heater tank is full) before turning on the water heater. That has worked for 21 years with no bad results.

Same deal with shore water. Turn it on at the coach shore water entrance and then start the water heater.

I am not aware of a way to turn off the water flow to the water heater, but I have never needed that ability either.

Actually, I only drain the water heater tank water 1x per year to clear out the junk it accumulates.

I forgot about turning on the water pump in the coach as a part of the process when off grid. So, I imagine when the water pump is turned on it fills the water heater with water. Opening a faucet, prior to turning on the water heater switch, I would imagine clears out any air in the system. How long does it take your unit to heat the water? I'm assuming it's a propane heater with DSI.

Floridastorm · 01-16-2023, 12:22 PM

Just tested out my water heater and it worked perfectly. Takes about 15 minutes or longer to heat the water to hot. So, think I will stick with my current water heater instead of having a new one installed.

Thanks for your assistance.

Old Man Dave

deandec · 01-16-2023, 05:27 PM

Unless you have a water heater tank leak or have drained the water heater for some reason, there will always be water in the water heater tank in my experience.

Jon_C · 01-16-2023, 06:00 PM

Quote:

Originally Posted by Floridastorm

Just tested out my water heater and it worked perfectly. Takes about 15 minutes or longer to heat the water to hot. So, think I will stick with my current water heater instead of having a new one installed.

Thanks for your assistance.

Old Man Dave

Mine is 25 and still kicking.

Just open the faucet on hot side and if air comes out, leave it open till just water comes out, then turn heater on. It should stay full unless drained.

Mudfrog · 01-17-2023, 08:35 AM

As long as the water heater isn't bypassed, the process of filling the water heater is the same whether connected to city water or pumping from the tank. As mentioned, open a hot water faucet and wait for a steady stream of water to come out. Then flip the switch for the water heater.

Edited to add: The Atwood in ours turns 20 years this month.

Old-Biscuit · 01-18-2023, 04:27 PM

City Water & Pump discharge go to SAME cold water line which feeds the water heater (bottom inlet port) which then feeds the hot water line (top outlet port)
So with either one you have to open a faucet and bleed air out so tank can fill

Water heater tank has an Air Pocket that helps control pressure increases (water swells when heated...no air pocket and T&P Relief Valve can 'weep')

Electric has a recovery rate of 6 gals/hr from initial fill temp (70*F)
Gas has a recovery rate of 10 gals/hr from initial fill temp)
BOTH together...roughly 16 gal/hr recovery rate

**Electric element will burn out if DRY fired so also make sure WH Tank has water in it