draining a hot water heater with no drain

Tedsoldbus · 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.

belfert · October 23, 2021, 05:40:27 PM

Are you talking about the pressure relief valve?

Tedsoldbus · 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...

lostagain · 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?

Dave5Cs · October 23, 2021, 06:47:00 PM

Pop-off valve is what we call them here.

Utahclaimjumper · 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

Tedsoldbus · October 24, 2021, 04:50:38 AM

Its electric, no anode, no bypass plumbing......yet.

richard5933 · 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?

luvrbus · 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

richard5933 · 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.

luvrbus · 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

Utahclaimjumper · 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

luvrbus · 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

Van · October 24, 2021, 12:05:45 PM

All we know
https://youtu.be/UY8H0KrwDlE

Tedsoldbus · 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..