Why Are My Tank Heaters Only Drawing 2 Watts in Warm Weather?

[Ben01110]

Hi, new here, so far my claim fame is being the only person with a "serenova" camper on this forum - yes - it is Grand Design. And yes, I love it minus a few quirks..

Anyway, I've tested everything I can, it all works. However, my camper shipped with tank heaters. And my manual doesn't mention them at all.

I push the control panel button to turn the fresh water tank, monitoring energy draw from my victron shunt, and energy demand increases by 2 watts. 2. So I turn on the gray tank heater, and, energy demand explodes to two more watts. I'm assuming this runs off of the 12 volt system.

Is that it? Does this confirm it's working? Does energy draw go up when it is cold (here in San Diego it's been in the 80s)? Or does it just barely sip energy like that? Thanks much!

 

[jkwilson]

Should be closer to 60W each

 

[trailrydr]

Hi, new here, so far my claim fame is being the only person with a "serenova" camper on this forum - yes - it is Grand Design. And yes, I love it minus a few quirks..

Anyway, I've tested everything I can, it all works. However, my camper shipped with tank heaters. And my manual doesn't mention them at all.

I push the control panel button to turn the fresh water tank, monitoring energy draw from my victron shunt, and energy demand increases by 2 watts. 2. So I turn on the gray tank heater, and, energy demand explodes to two more watts. I'm assuming this runs off of the 12 volt system.

Is that it? Does this confirm it's working? Does energy draw go up when it is cold (here in San Diego it's been in the 80s)? Or does it just barely sip energy like that? Thanks much!

Never had them on our 5er tanks, but, could they possibly be "thermostatically" controlled?

In other words... only come on when temps are (alot) lower than say.... 80 degrees fahrenheit? Maybe staying in a "standby" mode until needed drawing only a parasitic load?

 

[Scott'n'Wendy]

Depends on the ambient temperature if they are self regulating. With self regulating heat trace (pads) if the surface they are trying to heat is above freezing or whatever temperature they were designed for....they draw less current. I don't know if your pads are self regulating...I expect they are... but test them the same way when it is cold out....you might get a different reading.

 

[Ben01110]

thanks all.. this morning in San Diego it was a very chilly 59 degrees, I even had to put on shoes. Tried the fresh water tank heater, 2 watts. But the gray tank is reporting as 1/3 full, which was a surprise, and when i turned on the gray tank heater, energy use spiked to 60 watts and then settle down to about 5 watts. The fresh water tank has less than 10 gallons in it, so that tank is probably going to be much closer to ambient temp.

Anyway, thanks much all! I think I have the answer I need. Just wanted to make sure they did work, and it looks that way.