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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Tedsoldbus on October 23, 2021, 05:27:36 PM

Title: draining a hot water heater with no drain
Post by: Tedsoldbus on October 23, 2021, 05:27:36 PM
My 6 gallon has no drain. I have been putting 8 gallons of anti freeze in the water tank and running the hot spigots so the HW heater is full of anti freeze. Learned from a young plumber today that was going to cut my copper HW line and put a valve in it for me, that since my popit valve has a pipe that goes down and out the bottom of the bus, I could drain it: Drain the water tank. Open the popit valve. Open the sink hot water spigots. Turn on the water pump. To my amazement, the hot water tank drained completely. Now I can use about 3 gallons of anti freeze to do the whole system and it gives me a way to flush my HW tank with white vinegar and then be able to drain it. Not ready to winterize yet but now I know how. I expect not every popit valve has a drain line out the bottom, but I hope this helps someone else.
Title: Re: draining a hot water heater with no drain
Post by: belfert on October 23, 2021, 05:40:27 PM
Are you talking about the pressure relief valve?
Title: Re: draining a hot water heater with no drain
Post by: Tedsoldbus on October 23, 2021, 05:58:23 PM
Yep, Thats what I thought it was called. Plumber called it popit...... but then, I am in Georgia...
Title: Re: draining a hot water heater with no drain
Post by: lostagain on October 23, 2021, 06:16:57 PM
You don't say what kind of water heater it is, but if it is propane, there should be an anode rod near the bottom that you remove to drain it.

And could you not bypass the heater, after you drain it, so as not to fill it with antifreeze?
Title: Re: draining a hot water heater with no drain
Post by: Dave5Cs on October 23, 2021, 06:47:00 PM
Pop-off valve is what we call them here. :^
Title: Re: draining a hot water heater with no drain
Post by: Utahclaimjumper on October 23, 2021, 07:52:27 PM

If it's a Dometic it will have an anode rod,, an Atwood does not..Propane or not..  The difference is the Atwood has an aluminium tank..>>>Dan
Title: Re: draining a hot water heater with no drain
Post by: Tedsoldbus on October 24, 2021, 04:50:38 AM
Its electric, no anode, no bypass plumbing......yet.
Title: Re: draining a hot water heater with no drain
Post by: richard5933 on October 24, 2021, 05:24:38 AM
Depending on how you installed the thing it might be possible to just pull it out for the winter and stick in an jumper hose between the two lines for winterizing.

Never seen an RV style water heater without a drain plug. Did you use a tiny residential heater?
Title: Re: draining a hot water heater with no drain
Post by: luvrbus on October 24, 2021, 05:43:04 AM
He probably has a Seaward Marine water heater they didn't have drains till more recently used Stainless tanks.no anode  no propane either. You can plumb those to the engine to make hot water,they make cheaper models now that does have the anode,good water heaters and pricy the all S/S is around a 1000 bucks now 
     
Title: Re: draining a hot water heater with no drain
Post by: richard5933 on October 24, 2021, 06:53:50 AM
Quote from: luvrbus on October 24, 2021, 05:43:04 AM
He probably has a Seaward Marine water heater they didn't have drains till more recently used Stainless tanks.no anode  no propane either. You can plumb those to the engine to make hot water,they make cheaper models now that does have the anode,good water heaters and pricy the all S/S is around a 1000 bucks now 
   

The Seaward has been in our bus for at least as long as we've owned it (4 years) and it has a drain valve.
Title: Re: draining a hot water heater with no drain
Post by: luvrbus on October 24, 2021, 07:03:28 AM
Quote from: richard5933 on October 24, 2021, 06:53:50 AM
The Seaward has been in our bus for at least as long as we've owned it (4 years) and it has a drain valve.

Ok whatever but I have 2  in the shop that do not have a drain,if has the rear heat exchanger I never saw one with a drain till lately with the cheap @$# plastic drain hose bib   
Title: Re: draining a hot water heater with no drain
Post by: Utahclaimjumper on October 24, 2021, 10:48:33 AM

I'm thinking it would still have a pressure relieve valve that could be removed and a small hose inserted into the hole to siphon out the contents..>>>Dan
Title: Re: draining a hot water heater with no drain
Post by: luvrbus on October 24, 2021, 11:11:56 AM
Quote from: Utahclaimjumper on October 24, 2021, 10:48:33 AM
I'm thinking it would still have a pressure relieve valve that could be removed and a small hose inserted into the hole to siphon out the contents..>>>Dan

You can always remove the heating element it's easy to remove unless some idiot installed it with the element against a wall
Title: Re: draining a hot water heater with no drain
Post by: Van on October 24, 2021, 12:05:45 PM
All we know
https://youtu.be/UY8H0KrwDlE
Title: Re: draining a hot water heater with no drain
Post by: Tedsoldbus on October 24, 2021, 04:07:14 PM
I believe the brand is suburban. The booklet does not show a drain. The cold line going in and hot going out are copper. They disappear straight up into the floor and are "welded" ( I know that is not what they call it but you get it.). Feed line going from tank and shore pressure line is 1/2 plastic and half copper. Its a fiasco. Topping all that, the feed line to the hot water heater goes in behind the cabinet where the hot water tank sits. Both drain pipes for grey and black are in front of all of that water plumbing and the two water pumps. I have to get the neighbor kid with little hands to help me change the water filter which is of course at the very back of all that...! (Thanks Foretravel.) It is a mess. But....this...I can fix! I know how!
Setting timing on the 6V92? Not happening. Tearing into the HT 740 Allison? Forgetaboutit....
What the plumber taught me will do for now. Not changing the hot water heater while it still works so very well. Have enough to work on without diving into things that are not broken..
Title: Re: draining a hot water heater with no drain
Post by: oltrunt on October 24, 2021, 06:05:16 PM
Somehow I've never learned that lesson---I'll keep working at it until it IS broken and then replace it all. :-[  Jack
Title: Re: draining a hot water heater with no drain
Post by: dtcerrato on October 24, 2021, 06:56:44 PM
That's my moto - if it ain't broke don't fix it. Some would cringe but anyway - we've owned our only coach for 42 years & 6 months. We have never changed nor replaced the brake blocks because they exceed da book's minimum thickness, there are still a few of the original convoluted air bellows on it because they refuse to quite giving perfect service, same for a LOT of oem equipment on it so yes I agree.  8)
Title: Re: draining a hot water heater with no drain
Post by: chessie4905 on October 25, 2021, 05:41:05 AM
You do inspect bellows occasionally for cracking?
Title: Re: draining a hot water heater with no drain
Post by: dtcerrato on October 25, 2021, 12:49:10 PM
Yes on bellows crack inspection. Yes on cracks on exterior surface of older bellows. Yes on exterior cracks (within reason) being acceptable by the manufacturers. Yes on the older vintage bellows being heavier & thicker than newer bellows. Blistering &/or bubble are not acceptable.