Community Forums

cavie · 09-02-2018, 07:58 AM

I run my WH strickly on Propane being a season site and the cost of electricity. Propane is cheap around here. Did the math.

Anyway, I been thinking about the statement that you can run the electric at the same time as the gas on the WH. Now. for the sake of argument I will agree with that. You can have both on with no damage. However, my thought on jt is that in reality, they both will not come on ay the same time and here is why. I very well may be wrong but here goes.

There are 2 thermostats with a plus or minus accuracy of X degrees one way or the other. I dought seriously they are exactly the same. Let us say the gas comes on first and starts heating the water. What is going to turn on the electric if it has a lower preset temp say 2 degrees. The gas being on is gonna heat the water and keep the electric from turning on yes? What are your thoughts on this??

twinboat · 09-02-2018, 08:05 AM

If you exchange the water faster then the gas can heat it, the water temp can drop enough to kick in the second thermostat.

sbleiweiss · 09-02-2018, 08:07 AM

WE use both when showering or washing dishes. We only have a 6 gallon tank. When it is be used heavily the water temp will drop substantially what with all the cold makeup water being added. They both run. It makes a noticeable difference. And hasn't hurt anything in 3-4 years. A factory tech told us to do this.

leroybrown · 09-02-2018, 08:13 AM

You can use both, and with a long high use of hot water they both will come on and your recovery time will be faster, hence longer time before you run out of hot water. When we had the Baystar, the electric would come on first, and always keep the water hot with low useage. But take a long shower and the electric couldn’t keep up and the gas would also kick on. Almost like a tankless heater, it heats as you use the hot water. But you will run out with a long shower as they both can’t keep up with a long high demand.

puttin · 09-02-2018, 08:54 AM

Cavey,

Your electric heating element will come on at the same time the propane does. You can verify this using an amp probe on a vom, or in my case I can look at my ems and it will show approx 12 to 14 amp draw- both at the surge protector and inside at the Intellitec display.

rk911 · 09-02-2018, 09:04 AM

when parked with FHU we leave the WH on elec to save on consumables. when one of us completes a shower i’ll engage the gas WH to shorten recovery time. how do i know borh are operating simultaneously? i can see the amp draw on the electric side and i can hear the sound of the burner igniting on the gas side.

Old-Biscuit · 09-02-2018, 12:06 PM

Suburban uses two sets of t-stats....one 120V AC/electric & one 12V DC/propane.
Yes there can be 'variances' in those t-stats
Both sets are rated at 130*F/OPEN and 100*F/CLOSE
IF both switches are turned ON.........you will find that both operate at same time.
rarely will you find enough spread in temp settings that only one functions

Atwood........since 2004 all models use ONE set so both electric/propane are controlled by same set of t-stats so both come on/off same time
140*F/OPEN & 110*F/CLOSE standard models
160*F/OPEN and 130*F/CLOSE EXT Models (mixing valve set for 130*F output)

Either Brand Recovery rates (initial fill cold)
Electric ---- ~6 gal/hr
Propane --- ~10 gal/hr
BOTH ------ ~16 gal/hr