Q: Replacing a dip tube in a gas water heater

[NoWater]

Hello,

Would like to get some advice about replacing a dip tube in my heater. It is from 1996 or so. Please see the attached pictures.

Can I do this without cutting the water pipe? Any specific things to consider? Step-by-step instructions would be appreciated.

The heater information:
Model: FSG 40 232 v.s. cap Gal. 40
Part no: FSG--40-F00N010000

Spoiler: Here are the pictures...

Thank you!

 

[TomFOhio]

You won't have to cut any pipes. Turn the WH to pilot. Turn the cold water off coming out of the
wall on the cold side. You'll have to drain a bucket of water out to keep from having a mess at the bottom drain valve. Now, the dip
tube is on the cold side. You can take that nut off and that will unhook the water line to the nipple. The problem
is that the dip tube attached to that nipple coming out of the water heater is the length of
the water heater. Do you have that much height above the heater? You can buy a new plastic dip tube attached
to a nipple. If the dip tube is not attached to the nipple on the WH then you can grab it with needle nose pliers and hopefully
pull it out. You might have to easily bend it a little to get it out and the same to put the new one in. Hope I didn't confuse you.

 

[Jeff Handy]

Time for a new heater, you would be throwing good money after bad.

23 years old is too old.

 

[NoWater]

You won't have to cut any pipes. Turn the WH to pilot. Turn the cold water off coming out of the
wall on the cold side. You'll have to drain a bucket of water out to keep from having a mess at the bottom drain valve. Now, the dip
tube is on the cold side. You can take that nut off and that will unhook the water line to the nipple. The problem
is that the dip tube attached to that nipple coming out of the water heater is the length of
the water heater. Do you have that much height above the heater? You can buy a new plastic dip tube attached
to a nipple. If the dip tube is not attached to the nipple on the WH then you can grab it with needle nose pliers and hopefully
pull it out. You might have to easily bend it a little to get it out and the same to put the new one in. Hope I didn't confuse you.

Tom,

Thank you for the explanation. It makes perfect sense. I don't have enough overhead space for a full length tube, but when I called a local plumbing supply store, they said they have flexible tubes. They didn't mention anything about the nipple, though. Do those tubes really come with pre-attached nipples? If so, by what means? Glued on?

 

[NoWater]

Time for a new heater, you would be throwing good money after bad.

23 years old is too old.

Jeff,

That's an option, I agree. I just wanted to try to do a simple repair first, if possible.

The funny thing is, about 3 years ago, the bottom drain valve decided to break off on its own out of blue, causing a huge mess, as you would imagine. I was away, but luckily not for long, and when I came back home, I had a stream of water coming into the street from underneath my garage door. An unbelievable amount of limescale was everywhere. I asked the repairman about getting a new heater back then, but he didn't think that was necessary. "Hey, at least you have it fully flushed now," he laughed.

I have had no issues with this heater, aside from a limited supply of hot water when using the shower at full speed, which led me to believe that the dip tube has gone bad at some point years ago.

 

[Jeff Handy]

Limited hot water could be from a thick scale deposit covering the bottom and maybe the flue pipe.

Lack of hot shower water could be a bad shower cartridge, or cartridge has a high limiter that needs to be adjusted higher.

The drain valve rotting off was a big warning, I would have ditched the heater at that time.

But to each his own.

 

[NoWater]

Limited hot water could be from a thick scale deposit covering the bottom and maybe the flue pipe.

Lack of hot shower water could be a bad shower cartridge, or cartridge has a high limiter that needs to be adjusted higher.

The drain valve rotting off was a big warning, I would have ditched the heater at that time.

But to each his own.

Actually, I did not notice any difference after the tank was fully flushed from all that limescale. The hot water runs fine for about 5 minutes in the 2.5 gpm shower, but then gets cold. It is not like it is lukewarm all the time.

My other (main) shower had a head with a limiter, so it could be used for much longer. I just replaced that shower head with a more powerful one, as the old one started leaking. I've had no issues with blocking buildup anywhere, however, so it is not that, I presume.

 

[Jeff Handy]

By hot limiter, I mean that some valves have a disk or other physical stop that can be adjusted, so you can turn up the concentration of hot water as the hot water supply begins to cool.

Old lime scale can harden like thick rock, and is often not flushable.

 

[NoWater]

By hot limiter, I mean that some valves have a disk or other physical stop that can be adjusted, so you can turn up the concentration of hot water as the hot water supply begins to cool.

Old lime scale can harden like thick rock, and is often not flushable.

Jeff,

Where would such a limiter be located? Thanks!

 

[TomFOhio]

On the dip tube some come attached to the nipple by some means at the factory. Then also you can get them where
they have a flair at one end so it won't fall down in the tank and then you screw your nipple on top of the dip tube flair.

 

[Jeff Handy]

It is usually a small disk that sits on the stem of the cartridge, behind the handle or trim pieces.
So not visible until that stuff comes off.

Some can just be pulled off and put back on in a different position.
Some have a set screw, or other method of adjustment.
Some really old trims have other types of limiters.

Post some pics of your shower valve trim and handle.
And tell us brand name and model if you know it.

 

[NoWater]

On the dip tube some come attached to the nipple by some means at the factory. Then also you can get them where
they have a flair at one end so it won't fall down in the tank and then you screw your nipple on top of the dip tube flair.

I see. You mentioned the Pilot mode. Is that mode enough? Do I need to shut off the gas completely and re-light the burner later on?

There is a knob on the control unit which has 3 positions (ON/PILOT/OFF) - currently in ON, obviously. There is also the red valve on the gas line itself.

 

[TomFOhio]

If you feel more comfortable shutting the red handle valve off to the water heater go ahead. You will have to
re-light the water heater which is no big deal. Which ever you try first, working on the shower faucet or replacing
the dip tube let us know if we helped you any on this problem. Good Luck......

 

[Copymutt]

Some have the dip tube welded in place, not replaceable. State brand is one. Design by expected unit life.

 

[havasu]

Doesn't seems wise to spend this time and trouble for something that may give you another year before going kaput.

 

[NoWater]

It is usually a small disk that sits on the stem of the cartridge, behind the handle or trim pieces.
So not visible until that stuff comes off.

Some can just be pulled off and put back on in a different position.
Some have a set screw, or other method of adjustment.
Some really old trims have other types of limiters.

Post some pics of your shower valve trim and handle.
And tell us brand name and model if you know it.

Jeff,

Both on/off valves are good ol' Moens, each with a 1225 cartridge, nothing fancy.

The old high-flow shower head did not have any rings inside, not even a screen. I threw it away and replaced with an economy (1.8 gpm) plastic Niagara with a hose. I dodn't use that bathroom, but like to have a hose now for when I need it.

The main shower had an old plastic Moen with a hose, it only had a screen inside, I think. I replaced it with a high-flow all-metal HammerHead: https://www.theshowerheadstore.com/products/all-metal-hand-held-shower-head-set

It had a flow restrictor inside: 2 little rings, a plastic one and a smaller rubber one. See the attached picture. Per manufacturer's advice, I removed both of these, and only left the screen in. My guess is these are what you were referring to? Is the small rubber ring supposed to swell at high temp further restricting the flow? Would appreciate any insight about this.

I like the new head so far. If it lasts like they claim it would, it is a steal for $55.

Thank you!

Spoiler: Pictures are here

 

[Jeff Handy]

I am NOT referring to anything in the shower heads or shower wand.

Unless your valves are really old Moen, they will have a high limit disk right behind the handle.
Also, if you have a Moentrol valve it has a pressure balancing cartridge that can go bad.
It can be either at the top or right side of the valve.

Read these FAQ from Moen’s site.

https://www.moen.com/customer-support/faq/faq-135

If you have ancient Moen they might not have high limiter or pressure balancer.

 

[NoWater]

I am NOT referring to anything in the shower heads or shower wand.

Unless your valves are really old Moen, they will have a high limit disk right behind the handle.
Also, if you have a Moentrol valve it has a pressure balancing cartridge that can go bad.
It can be either at the top or right side of the valve.

Read these FAQ from Moen’s site.

https://www.moen.com/customer-support/faq/faq-135

If you have ancient Moen they might not have high limiter or pressure balancer.

Jeff,

Thanks, but I don't have anything like that.

 

[NoWater]

If you feel more comfortable shutting the red handle valve off to the water heater go ahead. You will have to
re-light the water heater which is no big deal. Which ever you try first, working on the shower faucet or replacing
the dip tube let us know if we helped you any on this problem. Good Luck......

So far, no luck. The supply line came off just fine, but the tube nipple won't budge. I sprayed some PB Blaster on the bottom thread prior to my first attempt and left it there for about 40 minutes. Tried turning the nipple in both directions, but it won't move. Added more PB after that, will try again after a few hours. If that still doesn't work, I will accept the defeat.

 

[NoWater]

UPDATE: Just replaced the water heater; it was a fairly straightforward job. The hardest part was to lift it up to the stand.

I peeked inside the old WH. The cold nipple is all by itself, there is no dip tube attached to it. The tube seems to have broken off completely some years ago. I am not surprised...

Thank you, everyone!