Hot water heater question

[wallyuwl]

Currently my house is getting repiped, so figured might as well replace the water heater as we have had some problems with it the last few years. It is a 400 series AO Smith, 2016 model year. A gravity fed hot water recirculation line was feeding into the drain valve. Part of the house was repiped already, and they removed the recirc line. Ever since we get at best lukewarm water, which I think might be due to the cold mixing with the hot since the heat trap was removed during install of the original recirc line?

I will have a gravity fed recirc line plumbed into the drain valve just like before. Our system is a well, and the only check valve in the system is just after the water gets into the house from the well, before even the pressure tank.

I plan to replace with the same water heater (only 410 model, but essentially the same thing, $900), or else a Richmond Essentials Plus model from Menards ($600). Might consider an AO Smith from Lowes (Signature 100 series, $620). Thoughts on any of these?

Today I stopped into the plumbing business where the former house owners bought the AO Smith. I was told that there is a heat trap (he called it a check valve) that needs to get taken out of the hot water nipple on top of the tank if you have a gravity fed recirc line. But it doesn't need to get taken out if you have a pump. The way the AO Smith ones are now made the heat trap is easy to remove, not so easy on the Richmond since the nipple needs to be removed. BTW, he said maybe the thermostat went bad on the gas control valve, causing the lukewarm water. I donno.

I'm having a hard time understanding why the heat trap needs to be removed (he didn't really explain it)? It doesn't seem to make sense to me, since doesn't the heat trap just keep water from going back into the tank?

My questions are:

1. Thoughts on those water heaters?
2. Do I need to remove the heat trap on the hot?
3. Any ideas on if removing the recirc line would case the lukewarm water we've had ever since it was removed (due to the existing water heater not having heat trap), or if it could coincidentally be a bad thermostat?

Thanks.

 

[skyactiv]

Get a Bradford White from a plumbing supplier.

 

[Gyro Gearloose]

The heat trap nipple has a ball in a cage or flap that closes off the pipe when there is no flow. The pressure differential created when you open a faucet will open the trap and let water flow normally but convection currents carrying hot water up the pipe do not provide enough force to lift the ball. A convection recirc system would intentionally be prevented from working.

 

[AZjeff]

Curious when you're having plumbing work done you wouldn't put a recirc pump in the hot loop? Do you get instant hot water with the convection recirc?

 

[wallyuwl]

The heat trap nipple has a ball in a cage or flap that closes off the pipe when there is no flow. The pressure differential created when you open a faucet will open the trap and let water flow normally but convection currents carrying hot water up the pipe do not provide enough force to lift the ball. A convection recirc system would intentionally be prevented from working.

Thanks. So you're saying that the flap/ball needs to be removed for a gravity recirc line to work?

 

[97prizm]

Currently my house is getting repiped, so figured might as well replace the water heater as we have had some problems with it the last few years. It is a 400 series AO Smith, 2016 model year. A gravity fed hot water recirculation line was feeding into the drain valve. Part of the house was repiped already, and they removed the recirc line. Ever since we get at best lukewarm water, which I think might be due to the cold mixing with the hot since the heat trap was removed during install of the original recirc line?

I will have a gravity fed recirc line plumbed into the drain valve just like before. Our system is a well, and the only check valve in the system is just after the water gets into the house from the well, before even the pressure tank.

I plan to replace with the same water heater (only 410 model, but essentially the same thing, $900), or else a Richmond Essentials Plus model from Menards ($600). Might consider an AO Smith from Lowes (Signature 100 series, $620). Thoughts on any of these?

Today I stopped into the plumbing business where the former house owners bought the AO Smith. I was told that there is a heat trap (he called it a check valve) that needs to get taken out of the hot water nipple on top of the tank if you have a gravity fed recirc line. But it doesn't need to get taken out if you have a pump. The way the AO Smith ones are now made the heat trap is easy to remove, not so easy on the Richmond since the nipple needs to be removed. BTW, he said maybe the thermostat went bad on the gas control valve, causing the lukewarm water. I donno.

I'm having a hard time understanding why the heat trap needs to be removed (he didn't really explain it)? It doesn't seem to make sense to me, since doesn't the heat trap just keep water from going back into the tank?

My questions are:

1. Thoughts on those water heaters?
2. Do I need to remove the heat trap on the hot?
3. Any ideas on if removing the recirc line would case the lukewarm water we've had ever since it was removed (due to the existing water heater not having heat trap), or if it could coincidentally be a bad thermostat?

Thanks.

When I worked apartment maintenance the AO Smith and Whirlpool seemed to have the fewest issues and needed replacement the least. Rheem seemed to be replaced the most.

 

[mk378]

Part of the house was repiped already, and they removed the recirc line.

So you don't have a recirculation system at all any more? It's now just conventional once through the heater to the tap?

 

[KevinMalone]

Get a Bradford White from a plumbing supplier.

Just a heads up that the anode on my BW tank is part of the hot water outlet and is a huge pain to replace. I don't think I will go with another BW tank next time due to this

 

[oil pan 4]

If the water coming out of the hot water heater is hot, then it's not the hot water heater.
Drain all the junk out of it, put a new anode in it and run it for another 12 years and fix or block off that recirculation line.
I had similar problems when I installed a hot water recirculation pump. I ended up using a check valve and a solenoid.
First attempt I put the pump in. Got a lukewarm shower, wife was not happy, added solenoid valve, fixed that problem.
Second attempt, was getting warm water out the garden hose and didn't know it, that used all the hot water in the hot water heater watering the back yard, the shower was pretty cold, wife was not happy, added a check valve.
Now it works.

 

[oil pan 4]

Just a heads up that the anode on my BW tank is part of the hot water outlet and is a huge pain to replace. I don't think I will go with another BW tank next time due to this

Yeah get one where the anode has its own 3/4 or 1 inch pipe thread hole. Avoid that outlet/anode garbage.

 

[wallyuwl]

So you don't have a recirculation system at all any more? It's now just conventional once through the heater to the tap?

The recirc line was taken out with the portion of the repipe that is already complete. Right now it is just conventional, heater to tap (takes forever for even the warm water to get to the kitchen). But it is going to be put back in. The inlet for it will be on on the drain valve of the water heater, not on the cold line just prior to going into the heater (I guess the cold line is the other way to do it based on what I've seen). Previously it was attached to the drain valve.

 

[Tdbo]

Just a heads up that the anode on my BW tank is part of the hot water outlet and is a huge pain to replace. I don't think I will go with another BW tank next time due to this

Plus one. I hate the one that I have because the thermostat has two temperatures: cold and scalding hot.
Wish that I had bought another Rheem and saved $600. Never again.

 

[Gyro Gearloose]

Thanks. So you're saying that the flap/ball needs to be removed for a gravity recirc line to work?

Yup. The heat trap is designed to prevent the convection you are depending on.. As a side note, I'm not familiar with a gravity powered circulation arrangement like you describe, but without a check valve in the return line, I would think half your hot water would feed from the cold area of the water heater and you would never get truly hot water. On the other hand, the convection forces are pretty weak and I'm not sure they would open a check valve. But if it has worked fine for you in the past party on.

 

[JohnnyG]

Sounds to me like you are only getting hot water from the bottom feed line, which will almost never get hot.
The rest doesn't make any sense to me.
One thing for certain, in Wisconsin, you should avoid heat pump water heaters.

 

[burbguy82]

A gravity fed hot water recirculation line was feeding into the drain valve

It is not "gravity" so to speak it is where some people connect the hot water return line to a heater without using the proper check valves to isolate the hot and cold side of the domestic system.

Ever since we get at best lukewarm water, which I think might be due to the cold mixing with the hot since the heat trap was removed during install of the original recirc line?

This is possible. It could also be a bad shower valve cartridge, or if someone installed a "crossover valve" somewhere under a sink, likely the kitchen sink. It looks like an octopus thing, typically with hose connections. They are a way to retro fit a recirc system to a house that does not have a real one.

I was told that there is a heat trap (he called it a check valve) that needs to get taken out of the hot water nipple on top of the tank if you have a gravity fed recirc line. But it doesn't need to get taken out if you have a pump.

no.

1. Thoughts on those water heaters?
2. Do I need to remove the heat trap on the hot?
3. Any ideas on if removing the recirc line would case the lukewarm water we've had ever since it was removed (due to the existing water heater not having heat trap), or if it could coincidentally be a bad thermostat?

1.) either will be fine, I have had nothing but bad luck from BW heater in the past, so I do not recommend them specifically
2.) The "heat trap" is really a plastic extension of the inside of the nipple on the cold side. It feeds the water into the tank from the bottom, physics does the rest. Do not remove this nipple
3.)Gravity fed recirc lines suck. In fact i would go as far as to say that it should not even be a term. If you want hot water to the fixtures quicker, install a pump on the return line, if you have one. They can be expensive depending on several factors such as lineal pipe feet and head. Usually head does not matter unless you are talking 3 or 4 stories.


Are you doing the work yourself?

Send a picture of the water heater and all the associated piping from about 5 ft back. I will help you.

 

[oil pan 4]

Sounds to me like you are only getting hot water from the bottom feed line, which will almost never get hot.
The rest doesn't make any sense to me.
One thing for certain, in Wisconsin, you should avoid heat pump water heaters.

I would recommend avoiding them everywhere.

 

[Rand]

I would recommend avoiding them everywhere.

Why?

 

[awguy]

They've got heat pumps that work well in very cold temps now, or get a hybrid heat pump that can automatically work as a regular heater if needed.

 

[oil pan 4]

Why?

Over priced, over complicated, plumbers don't want to work on them, HVAC people don't want to work on them. My appliance repair guy says his 2 favorite things are heat pump dryers and heatpump hot water heaters.
But what does he know, always playing with his Corvette collection....

 

[wallyuwl]

It is not "gravity" so to speak it is where some people connect the hot water return line to a heater without using the proper check valves to isolate the hot and cold side of the domestic system.

This is possible. It could also be a bad shower valve cartridge, or if someone installed a "crossover valve" somewhere under a sink, likely the kitchen sink. It looks like an octopus thing, typically with hose connections. They are a way to retro fit a recirc system to a house that does not have a real one.

View attachment 240726

no.

1.) either will be fine, I have had nothing but bad luck from BW heater in the past, so I do not recommend them specifically
2.) The "heat trap" is really a plastic extension of the inside of the nipple on the cold side. It feeds the water into the tank from the bottom, physics does the rest. Do not remove this nipple
3.)Gravity fed recirc lines suck. In fact i would go as far as to say that it should not even be a term. If you want hot water to the fixtures quicker, install a pump on the return line, if you have one. They can be expensive depending on several factors such as lineal pipe feet and head. Usually head does not matter unless you are talking 3 or 4 stories.


Are you doing the work yourself?

Send a picture of the water heater and all the associated piping from about 5 ft back. I will help you.

View attachment 240725

Attached are pics.

Just a little more info. I released some water from the tank using the T&P valve to check temp. It is similar to at the shower (so not very hot).

The previous recirculation line was attached with a fitting to the drain valve. It went down right next to the TP valve tube. The drain valve in the pic is new. The plan is to add a fitting to this to attach a recirc line again.

I want to try to hook up like things were before, since it all worked fine. If necessary will add a pump.

No "comfort valve" installed on any faucet.

After all I have learned today, I guess I just need to know if removing the heat trap on the hot ripple is necessary or not?