another hot water tank question

Bobby A

Well-known member
The last few days Ive found myself conserving energy and shutting off the switch on the inside of the coach to turn off the hot water tank after our morning showers and then turning it back on the following morning. I turned it off yesterday and this morning after turning it back on the water would not heat. Can anyone tell me what the problem is ?? I haven't tried useing propane to heat the water yet, I will wait till tomorrow to do that if no hot water then I guess we will be taking a cold shower.

Thanks,
Bobby A
 

brianharrison

Well-known member
Sounds like the heater element may have failed, or tripped a breaker. Heating water from cold (relative to just keeping it at temperature) requires the element to be "on" for a longer period of time. It may have created a prolonged resistance load and burnt out the element or tripped a breaker (got hot).

Check breaker and/or you may have to replace element.

Normal on/off should usually not create a problem; your element may have just been ready to go anyhow. They can scale off with hard water and usage and burn out after a while.

Hope this helps.

Take care,
Brian
 

JohnDar

Prolifically Gabby Member
You might check the thermal reset on the front of the water heater. It may have opened for some reason. That's the two black "buttons" out there, one is for the 120V and the other is for 12V operation.
 

Bobby A

Well-known member
Sounds like the heater element may have failed, or tripped a breaker. Heating water from cold (relative to just keeping it at temperature) requires the element to be "on" for a longer period of time. It may have created a prolonged resistance load and burnt out the element or tripped a breaker (got hot).

Check breaker and/or you may have to replace element.

Normal on/off should usually not create a problem; your element may have just been ready to go anyhow. They can scale off with hard water and usage and burn out after a while.

Hope this helps.

Take care,
Brian

Brian,
That certanly my be the case, we have very hard water hear at the campgrounds, how difficult is it to change the heating element ?? got a step by step procedure for someone who is slightly handy ??

I did turn on the propane for a minute to see if I could hear the burner, and I can, so at least I can get hot water for showers that way.

John,
are you suppose to press both black buttons at once ?? Well that is what I'm gonna attempt.

Well at least the a/c is working in this weather (knock on wood) I would rather have the hot water tank go kaput than the a/c during this hot spell we are in.
Stay cool everyone, I will post back in the next couple days.
 

brianharrison

Well-known member
Click here for the DSI manual - it shows the two high limit switchs John talked about as well as a schematic of where the electric element is located. Good luck. Just rememeber to shut off the electrical before you work on the heater (trip the breaker or disconnect from shore power. Be cautious of 12 volt circuit as well.

Take care,
Brian

PS - Speaking theoretically here, the resistance of a good element should be able to be calculated knowing heater wattage and voltage W=V*A & V=A*R. From the manual the DSI electric heater is 1440 W at 120V = 12 Amps; R=V/A=110/12=9.2 Ohms. Therefore a new 1440W element should have about 9-10 ohms resistance. I would think a blown element should have infinite resistance (open circuit) or very high resistance +50 ohms?

Something I've always wanted to test, but never got around to it.....

Brian
 

Bobby A

Well-known member
Click here for the DSI manual - it shows the two high limit switchs John talked about as well as a schematic of where the electric element is located. Good luck. Just rememeber to shut off the electrical before you work on the heater (trip the breaker or disconnect from shore power. Be cautious of 12 volt circuit as well.

Take care


PS - Speaking theoretically here, the resistance of a good element should be able to be calculated knowing heater wattage and voltage W=V*A & V=A*R. From the manual the DSI electric heater is 1440 W at 120V = 12 Amps; R=V/A=110/12=9.2 Ohms. Therefore a new 1440W element should have about 9-10 ohms resistance. I would think a blown element should have infinite resistance (open circuit) or very high resistance +50 ohms?

Something I've always wanted to test, but never got around to it.....

Brian

Thanks for the info Brian, I will get the part today and make an attempt on Friday or Saturday. What size socket is it ?? its my understanding it unscrews just like the anode rod ?? correct me if I'm wrong.
 

jbeletti

Well-known member
Thanks for the info Brian, I will get the part today and make an attempt on Friday or Saturday. What size socket is it ?? its my understanding it unscrews just like the anode rod ?? correct me if I'm wrong.

Bobby,

Here's the tool you need (link).

420420.jpg
 

cookie

Administrator
Staff member
PS - Speaking theoretically here, the resistance of a good element should be able to be calculated knowing heater wattage and voltage W=V*A & V=A*R. From the manual the DSI electric heater is 1440 W at 120V = 12 Amps; R=V/A=110/12=9.2 Ohms. Therefore a new 1440W element should have about 9-10 ohms resistance. I would think a blown element should have infinite resistance (open circuit) or very high resistance +50 ohms?

Something I've always wanted to test, but never got around to it.....

Brian
Brian, last winter my water heater stopped heating on electric. I did test the element and had 12 ohms resistance. So in theory it should have been good. Not. wound up replacing it and all was good.

Bobby, when I did replace the element and tightened it the rubber gasket must have distorted due to friction and I developed a leak there. I wound up putting a little plumbers lube on that rubber gasket and was able to tighten it without any distortion.

Pax
Dave
 

brianharrison

Well-known member
Brian, last winter my water heater stopped heating on electric. I did test the element and had 12 ohms resistance. So in theory it should have been good. Not. wound up replacing it and all was good.

Pax
Dave

Thanks Dave - I appreciate the info!. However I am now more intrigued than before about this theoretical calculation versus real life observations.

I may have to conduct an experiemnt to test this out further. I'm camping next weekend - I wonder what the DW would think if I wandered around with my multi meter and measured the resistance on everyone's water heater element. I wonder if this is a good way to make friends? :rolleyes:

Take care,
Brian

PS to Bobby - dont forget to displace the hot water with cold water and reduce the water pressure in the tank before you remove the element. I almost forgot this critical step one time when I went to remove my anode. Would not have been good.....
 

boatto5er

Founding VA Chap Ldr (Ret)
Thanks Dave - I appreciate the info!. However I am now more intrigued than before about this theoretical calculation versus real life observations.

I may have to conduct an experiemnt to test this out further. I'm camping next weekend - I wonder what the DW would think if I wandered around with my multi meter and measured the resistance on everyone's water heater element. I wonder if this is a good way to make friends? :rolleyes:

Take care,
Brian

PS to Bobby - dont forget to displace the hot water with cold water and reduce the water pressure in the tank before you remove the element. I almost forgot this critical step one time when I went to remove my anode. Would not have been good.....[/QUOTE]

I believe Jim Beletti has an interesting story along this line :angel:
 

Bobby A

Well-known member
Click here for the DSI manual - it shows the two high limit switchs John talked about as well as a schematic of where the electric element is located. Good luck. Just rememeber to shut off the electrical before you work on the heater (trip the breaker or disconnect from shore power. Be cautious of 12 volt circuit as well.

Take care,
Brian

PS - Speaking theoretically here, the resistance of a good element should be able to be calculated knowing heater wattage and voltage W=V*A & V=A*R. From the manual the DSI electric heater is 1440 W at 120V = 12 Amps; R=V/A=110/12=9.2 Ohms. Therefore a new 1440W element should have about 9-10 ohms resistance. I would think a blown element should have infinite resistance (open circuit) or very high resistance +50 ohms?

Something I've always wanted to test, but never got around to it.....

Brian

Thank you all for your info, I got the heating element today at General RV and had to go to H/Depot and get the removal tool, thanks Jim B for the pic. Can I just shut the circuit breaker off for the hot water tank ?? I hate to disconnect the hole trailer because its near 100 degrees today and I need to keep the a/c kicken !! Brian, what do you mean about the 12volt circuit ?? should I disconnect the battery ?? I wanna make sure I do this right cause its offly hot out there to be messing around. As I was going to get the parts my truck overhead gauge read 100 degrees. Maybe I should wait for a cooler day since I can get hot water from propane, but why put off till tomorrow what can be done today !! I know, I must be crazy !!
 

brianharrison

Well-known member
Yes you can trip the breaker in the 110V panel.

There is 12V power source and 110V power source that comes into the hot water heater. The 12 volt circuit is shown on Figure 7 of the manual (page 4); the 12V hots are 18 AWG red, common is black and ground is yellow. If you shut the hot water heater propane switch off, this will disable the 12V circuit as well.

For me, I would wait until tomorrow AM, say sunrise when it is cooler?.

Earlier I mentioned you may want to completly shut off the water heater (electric and propane) and open a hot water tap in the trailer until it runs cold. Then turn off your campground water tap, and open a tap in the trailer to reduce the water pressure in the system (leave it open until you finish replacing the element).

For start up, work backwards making sure the new electrical element is not turned on until all of the air is out of the system - ie turn on campground tap, check for leaks around the heater, open a tap in the trailer until a steady stream of water comes out the hot tap (ie no air). The new element will crater if you turn it on with air in the hot water tank.

Dave suggested putting a water based lubricant on the seal of the element before you tighten it down. Good idea - I usually just use spit, but any water based lubricant is fine.

Hope this helps.

Take care,
Brian
 

Bobby A

Well-known member
Yes you can trip the breaker in the 110V panel.

There is 12V power source and 110V power source that comes into the hot water heater. The 12 volt circuit is shown on Figure 7 of the manual (page 4); the 12V hots are 18 AWG red, common is black and ground is yellow. If you shut the hot water heater propane switch off, this will disable the 12V circuit as well.

For me, I would wait until tomorrow AM, say sunrise when it is cooler?.

Earlier I mentioned you may want to completly shut off the water heater (electric and propane) and open a hot water tap in the trailer until it runs cold. Then turn off your campground water tap, and open a tap in the trailer to reduce the water pressure in the system (leave it open until you finish replacing the element).

For start up, work backwards making sure the new electrical element is not turned on until all of the air is out of the system - ie turn on campground tap, check for leaks around the heater, open a tap in the trailer until a steady stream of water comes out the hot tap (ie no air). The new element will crater if you turn it on with air in the hot water tank.

Dave suggested putting a water based lubricant on the seal of the element before you tighten it down. Good idea - I usually just use spit, but any water based lubricant is fine.

Hope this helps.

Take care,
Brian

Thanks Brian for all you in dept information, I feel more and more confident doing this repair after reading your posts. Maybe I will wait till tomorrow, it did reach 100 degrees officially today in MI. The horn stayed a confortable 85 degrees inside and yes 85 is confortable when its 100 outside and high humidity. I can't ask for much more coming from one a/c unit.

Thanks a million Brian and everyone else who replied, I will post back when completed

Bobby A
 

rebootsemi

Well-known member
I believe all of the WH elements are rated at 1440 Watts, makes sense it's a 120 volt circuit. Knowing the Watts and volts you can figure out the resistance; Volts squared divided by Watts equals Ohms, so you should have around 10 ohms resistance on a good element.
 

jbeletti

Well-known member
In May 2009, I replaced one and documented the process with photos. Attached is one of those photos. 10.6 ohms is what I read on a new, unconnected element (120 volts / 1440 watts). Open or infinity is what I read on an unconnected blown element.

10.6 Ohms - Good Electric Heating Element.jpg

Jim
 

brianharrison

Well-known member
In May 2009, I replaced one and documented the process with photos. Attached is one of those photos. 10.6 ohms is what I read on a new, unconnected element (120 volts / 1440 watts). Open or infinity is what I read on an unconnected blown element.

Jim

Thanks Jim! I searched extensively for this topic as I was hoping someone had already completed a DIY but did not find your thread. Could you post a link for Bobby for the pics?

Take care,
Brian
 

jbeletti

Well-known member
Brian,

Sorry, but I never completed the written documentation. The shell of the article is in the Heartland Owners Wiki (HOW).

A heating element within the RV water heater (if so equipped) that heats the water using 110 volts AC power.

Description
An Element that is contained within the RV water heater (if so equipped) that heats the water using 110 volts AC power. The Element is user replaceable. Access to the electrical connections of the Element is made from outside the RV by removing the water heater cover, then removing a black plastic cover that protects the electrical connection.

Cautions
  • Never turn on the Electric Heating Element unless you are certain the water heater tank is filled with water. Failing this, within a few seconds, you will burn out the Element. Turn on a hot water faucet inside the RV and assuming the water heater is not bypassed, when you have water coming from the hot water faucet, it is safe to turn on the Electric Heating Element
  • Never attempt to remove the Electric Element until you have removed pressure from the hot water tank (open a hot water tap or pressure relief valve)
Tools required to remove the Anode Rod from a Suburban brand water heater
  • Water Heater Heating Element Tool (a very thin-wall socket type tool that is deep and includes a breaker bar/handle)
  • 7/16" Open End Wrench (used to remove burner tube assembly)
When to remove the Electric Element
  • When the Element is burned out and requires replacement
  • When you want to flush the tank from a higher point than the Anode Rod drain hole
Steps for removing the Electric Element
  • Turn off the water heater inside at the monitor panel
  • Turn off the AC power source to the water heater inside near the monitor panel and/or outside on the water heater itself
  • Turn off the gas supply to the water heater (by closing all propane tanks)
  • Remove water pressure from the water heater by either opening up a hot water faucet or opening the pressure relief valve on the water heater
  • Consider draining the water heater by removing the Anode Rod (1-1/16" socket, extension and socket wrench) - be sure the water is cool before attempting to remove the anode rod
  • Remove the small black plastic cover that protects the electrical connections to the Element
  • Disconnect the 2 electrical wires from the Element (polarity is not important so no need to mark wires)
  • Using a Water Heater Electric Heating Element Tool, rotate the Element counter clockwise. Element may be frozen in place. Keep inward pressure onto the Element while loosening it. Be sure to stand clear when the Element exits the drain hole to avoid water splash
Steps for installing the Electric Element
  • Prepare new Element by either applying potable water approved sealing compound to threads of Element or by applying Teflon thread sealant tape to threads of the Element
  • Insert new Element into Element hole and begin to thread in by hand being very careful to not cross-thread the Element into the Element hole
  • Using a Water Heater Electric Heating Element Tool, snug Element into Element hole, taking care to not over-tighten (torque not specified)
  • Reconnect both electrical wires
  • Replace protective cover over electric terminals
  • Replace burner tube assembly
  • If you removed the anode rod to drain, replace it
  • If you opened a hot water tap or water heater pressure relief valve, close it
  • If you bypassed the water heater, un-bypass it
  • Turn water back on to water heater to flood the tank. Test that tank is flooded by opening a hot water tap. When water comes out at its normal level for this location
  • Check for leaks around threads of the Element and correct as needed
  • Turn propane back on
  • Turn AC power switch(es) to water heater back on
  • Enjoy hot water soon!
Suburban Contact Information
 
Last edited:

Bobby A

Well-known member
Brian,

Sorry, but I never completed the written documentation. The shell of the article is in the Heartland Owners Wiki (HOW).

Simplified, my process was:
  1. Turn AC power off to water heater (WH)
  2. Turn water off to RV or use WH Bypass
  3. Relieve water pressure on WH either at a hot water tap or at pressure relieve valve on WH
  4. I had already drained the WH by removing the anode rod as I was replacing that too. Technically, you would not have to drain the WH, but it's always a good idea to drain it a few times a year and flush it out
  5. Remove black plastic protective cover from outside of element
  6. Disconnect (2 wires with terminals, held in place by 2 screws) wires from element
  7. Use WH element tool to remove element
  8. Clean threads on WH in element hole
  9. I wrapped teflon tape on threads of new element
  10. Insert new element and use tool to snug it up
  11. Reconnect both wires (I doubt polarity needs to be observed for this)
  12. Replace protective cover over electric terminals
  13. If you removed the anode rod to drain, replace it
  14. If you opened a hot water tap or WH pressure relief valve, close it
  15. If you Bypassed the WH, unbypass it
  16. Turn water back on to WH to flood the tank. Test that tank is flooded by opening a hot water tap. When water comes out at its normal level for this location, you're good
  17. Turn power switch(es) on to WH electric element
Miller time :)

Jim

On edit: Looks like I did finish the Wiki documentation, just have not added the images.

Thanks Jim for that COMPLETE play by play, that is AWESOME !! I will attempt this tomorrow evening or Saturday, one other question though, that socket tool is HUGE !! won't the tube for the propane get in the way ?? what do you use to put in the hole on the socket ?? like a screw driver or something to use as a braker bar ??

Thanks Brian for asking Jim to post pics, his detailed instructions are perfect.
Thanks guys. stay cool !!
Bobby
 

cookie

Administrator
Staff member
Bobby, you will have to remove the LP tube to get at the heater element. One nut and one fitting. 7/16 I think.

Peace
Dave
 

jbeletti

Well-known member
Good catch. Thanks Dave. I will add that to the written process later.

Bobby, a few more pics for you :)

Jim

Burner Tube Removal 1.jpgBurner Tube Removal 2.jpgBurner Tube Removal 3.jpgBurner Tube Removal 4.jpgBurner Tube Removal 5.jpgBurner Tube Removal 6.jpg
 
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