Relief Valve Drain Location

[HereInOhio]

I installed a tankless water heater. I know not recommended. Trying to figure out the best location to have the discharge for the relief valve with my given situation. There are no floor drains in this basement.

My preferred option is running it behind an 8’ wall and discharging into a utility sink located in the laundry room next to the utility room containing the water heater. This is where the condensation drain is routed. Going this route I would only have a few inches below the tank and relief valve before I needed to 90 horizontal to stay at a height above the sink. I thought I read it needs to be in the same room as the water heater though.

The other option is there’s a sump pump below the water heater but it will be sealed due to radon levels. Does the drain acts as a visual to see if something is wrong where I would need a clear pipe going this route? Would the air gap requirement be met?

Any ideas would be appreciated.

 

[HereInOhio]

I'm in IPC if it matters.

 

[Sponsor]

 

[Terry]

I've had inspectors mention that running them to a plumbing vent would be okay in a retrofit of an existing home.
Taking it to the laundry sink is better.

I have a tankless, and I do like not worrying about how long of a shower I'm taking.
My gas bill is $16.00 in the Summer.

 

[HereInOhio]

I've had inspectors mention that running them to a plumbing vent would be okay in a retrofit of an existing home.
Taking it to the laundry sink is better.

I have a tankless, and I do like not worrying about how long of a shower I'm taking.
My gas bill is $16.00 in the Summer.

Ok thanks. I didn't know how big of a deal it was that it wasn't in the same room but figured if it was labeled the functionality would be there. When you think about it, it makes more sense that you would find a leak in the sink of a room you are always in opposed to finding a leak a leak in a utility room that you never in. It's fine to 90 over immediately after it comes out of the bottom of the water heater? I didn't know if it needs to be a straight piece for so long once it exits.

Good to hear. I needed to replace my water heater and the price of them was around $700. Someone bought a $1,300 Rheem Platinum from the big box store but sold the house before they installed it. They sold it to me for $400. Plus I could install it in a favorable location and I'm probably selling the house soon so it will be energy efficient since I just replaced the HVAC with high efficient ones.

 

[Terry]

Make sure on the tankless install that you have the proper materials for the chimney. You can't use the old metal ones on tankless.

 

[Jeff H Young]

400 is a great price . there is no requirement that the termination of relief valve be within sight , nothing at all like that. but you don't want to terminate where damage can occur , just on the floor anywhere won't work .
did you look at instructions yet? venting? gas requirements? the tankless uses about 5 times as much gas 200k BTU vs around 40k BTU so if its next to a furnace you are looking at close to 300,000 BTU possibly on the gas pipe .
so before you start the install consider what's needed

 

[John Gayewski]

Termination on the sink is fine. Doesn't need to be in the same room.

 

[HereInOhio]

Make sure on the tankless install that you have the proper materials for the chimney. You can't use the old metal ones on tankless.

Yes, thank you. I vented it directly outside via PVC which was only a total of 3' distance so I should be good there. That factored in my decision of going with the tankless as well because although I had my chimney lined removing the furnace I think I would've had to drop a smaller liner down. Maybe not.

 

[HereInOhio]

400 is a great price . there is no requirement that the termination of relief valve be within sight , nothing at all like that. but you don't want to terminate where damage can occur , just on the floor anywhere won't work .
did you look at instructions yet? venting? gas requirements? the tankless uses about 5 times as much gas 200k BTU vs around 40k BTU so if its next to a furnace you are looking at close to 300,000 BTU possibly on the gas pipe .
so before you start the install consider what's needed

Good thing for me to remember if I get into another one in the future. In this case the incoming gas line (1 1/4") had a 1/2" branch for the water heater. I increased it to 3/4" and ran it to the tankless. The 1 1/4" continues on and tees off again to the furnace so I should be fine.

 

[HereInOhio]

Resurrecting this: I installed the tankless water heater and vented it through the side of the house. I have the sump pump that I need to put an air tight lid on which needs vented. I would like to vent it out right next to the WH vent, is there a distance I need to space these? Is a 1.5” vent sufficient? We are under IPC.

 

[John Gayewski]

Resurrecting this: I installed the tankless water heater and vented it through the side of the house. I have the sump pump that I need to put an air tight lid on which needs vented. I would like to vent it out right next to the WH vent, is there a distance I need to space these? Is a 1.5” vent sufficient? We are under IPC.

Don't vent your sump within ten feet of the water heat inlet.

 

[HereInOhio]

Don't vent your suump within ten feet of the water heat inlet.

I thought this may be the answer. I was trying to think of why it would have to be separated. My sump is only rain water and up to this point has been open to the basement. For the water heater inlet I would have to believe the air is fine considering it’s allowed to be open. I do realize I’m sealing it for a reason (radon) but it’s not like the WH exhausts any or it’s intake air into the house.

The reason that made the most sense to me was you wouldn’t want the WH exhaust to be drawn into the sump. Even though it’s sealed I could understand the reasoning here.

It would be much easier if I could put it a few feet away……

 

[John Gayewski]

I thought this may be the answer. I was trying to think of why it would have to be separated. My sump is only rain water and up to this point has been open to the basement. For the water heater inlet I would have to believe the air is fine considering it’s allowed to be open. I do realize I’m sealing it for a reason (radon) but it’s not like the WH exhausts any or it’s intake air into the house.

The reason that made the most sense to me was you wouldn’t want the WH exhaust to be drawn into the sump. Even though it’s sealed I could understand the reasoning here.

It would be much easier if I could put it a few feet away……

Most plumbing vents are almost always better vented through the roof.

Edit Correction: if your suump is just groundwater the venting should be able to go about anywhere there isn't exhaust.

 

[HereInOhio]

Most plumbing vents are almost always better vented through the roof.

Edit Correction: if your suump is just groundwater the venting should be able to go about anywhere there isn't exhaust.

Ok. Unfortunately there is the WH termination box (intake & exhaust) is right where I’m trying to put the sump vent. The WH intake/exhaust is right next to each other so I was hoping there was a way it exhaust that would allow me to put the sump vent closer, possibly sucking from the direction of the house like the WH intake.