Changing hot water check valve question

[dlewand53]

I have a 6 gallon Dometic/Atwood hot water heater. Electric and Gas. Thinking about changing check valve. Currently has plastic check valve which is causing some water flow problems when water is hot. Will use a brass check valve. Read about brass and aluminum tank aren't compatible over time. Has anyone had any experience or thoughts on whether this is a problem or not with using a brass check valve?

[RogerR]

You might ask by phone or email what the manufacturer recommends as a replacement. If they ok brass then why not.

[bucko]

I've always replaced the plastic drain plug with brass, so I'd think if you have a plastic check valve, that too would be fine using brass.

[us71na]

Brass and aluminum connected together shouldn't be a problem. The chart shows metal compatibility. If the intersecting square between the vertical listing of one metal to the other metal across the top is green, they are good to use together.

[dlewand53]

Thanks for all the responses so quickly. What a wealth of information. Now I can make the right decision for my RV. Take care everybody and have a great day.

[us71na]

If you look at your water heater, the safety valve is brass.....

[TCNashville]

Just curious but if you wrapped the threads of the brass check valve with teflon tape before installing it into the aluminum tank, would that help prevent any galvanic corrosion that may or may not occur? I'm thinking about doing this myself on my Atwood WH.

[us71na]

Originally Posted by TCNashville

Just curious but if you wrapped the threads of the brass check valve with teflon tape before installing it into the aluminum tank, would that help prevent any galvanic corrosion that may or may not occur? I'm thinking about doing this myself on my Atwood WH.

It is unlikely that the teflon tape would prevent all contact between the brass and the aluminum. Bass and aluminum play well together in wet environments.

[bucko]

Originally Posted by TCNashville

Just curious but if you wrapped the threads of the brass check valve with teflon tape before installing it into the aluminum tank, would that help prevent any galvanic corrosion that may or may not occur? I'm thinking about doing this myself on my Atwood WH.

Teflon tape is recommended to prevent any leaks under pressure. I'm sure if you did not use it, you would have drips, no matter how tight you wrench down.

[mavrick0]

Originally Posted by us71na

If you look at your water heater, the safety valve is brass.....

This isn't always the case. Our 2020 28.5rsts had a plastic one and because it had been over torqued was limiting the amount the valve would open and the flow of water. Replaced it with brass and not a problem after that.

[Yooper906]

Originally Posted by mavrick0

This isn't always the case. Our 2020 28.5rsts had a plastic one and because it had been over torqued was limiting the amount the valve would open and the flow of water. Replaced it with brass and not a problem after that.

Our 2022 28.5 RSTS water heater has a brass safety valve. I've never seen a plastic one on any of the trailers we've had, but this doesn't mean there aren't any, probably lots of things I've never seen.

[campersam9]

The plastic plug is used for a blow off. The pressure will blow the plug out. I will keep my plastic plug. Every 2 or 3 times with a new plug.

[Yooper906]

Originally Posted by campersam9

The plastic plug is used for a blow off. The pressure will blow the plug out. I will keep my plastic plug. Every 2 or 3 times with a new plug.

Are you talking about the plastic drain plug, or something else?

[mavrick0]

Originally Posted by Yooper906

Our 2022 28.5 RSTS water heater has a brass safety valve. I've never seen a plastic one on any of the trailers we've had, but this doesn't mean there aren't any, probably lots of things I've never seen.

I'm pretty sure we are talking about 2 different things. The OP was talking about the check/one way valve on the output of water heater that supplies water to the trailer.

The pressure relief valve located on the outside of the tank at the access door is for sure brass.

And I'm pretty sure what the other person is talking about with a plastic blow out plug is just the plastic drain plug. If that blows out before your pressure relief valve does it's job then you have bigger issues.

[dlewand53]

I was talking about the one-way check valve for the output of the hot water heater. From a couple of the replies it seems that changing the plastic over to a brass one will work just fine. I think the chart that one person posted about the compatibility between metals is the best information about putting a brass check valve into an aluminum tank. Thanks for everybody's replies. Have a good day.

[FireguyEd]

You can use PVC fittings between the tank and the check valve...

[DrSmart]

I'm just about to do this as well. Ordered 1 brass and 1 plastic, same as what's on the tank. Based on all the comments, I'm going to install the brass check valve with teflon tape and keep the black plastic one as a spare. My problem with the hot water flow, which completely stopped flowing at times, started the day after I changed the whole house filter. I'm thinking some crud went through the system after I changed the filter and interfered with the check valve. I'll see what's up when I pull the original valve.


Cheers

[icr21801]

Originally Posted by dlewand53

I have a 6 gallon Dometic/Atwood hot water heater. Electric and Gas. Thinking about changing check valve. Currently has plastic check valve which is causing some water flow problems when water is hot. Will use a brass check valve. Read about brass and aluminum tank aren't compatible over time. Has anyone had any experience or thoughts on whether this is a problem or not with using a brass check valve?

If you're having issues, change it now. The plastic one will fail. I ended up having to disassemble my basement 7 days into a 2 week trip at a remote camping area as our failed without warning. And depending on your rig they can be a bear to access.
$60K RV and they use a 25c plastic piece of junk for a the check valve.

I still carry a spare. Murphy's Law?
Murphy was an optimist lol.

[bucko]

Originally Posted by mavrick0

I'm pretty sure we are talking about 2 different things. The OP was talking about the check/one way valve on the output of water heater that supplies water to the trailer.

The pressure relief valve located on the outside of the tank at the access door is for sure brass.

And I'm pretty sure what the other person is talking about with a plastic blow out plug is just the plastic drain plug. If that blows out before your pressure relief valve does it's job then you have bigger issues.

This.

[Spower]

I replaced my plastic one with a brass one 2 yrs ago, no problems and fixed the hot water pressure issue.