Condensate line necessary in crawlspace for heat pump water heater?

[wcodyd]

Greetings. I’m installing a heat pump water heater in an unsealed crawspace. The crawspace stays generally dry and fairly warm (Arkansas) and has about six foot high ceiling where the unit will be installed. I’m removing an indoor hot water heater and replacing it with this heat pump water heater that will be installed in the crawspace.

The electrical is done. I’m tapping into cold and hot water lines that run directly over where the heat pump water heater will be installed. Here are my questions:

Since this is in the crawl space, I’m not planning to run plumbing to the pressure relief valve. I’m thinking this should be okay, right?

Similarly, since this is in the crawlspace, should I run a line for the condensate drain? I’m thinking it should be okay to leave without a line if there will not me much condensate. I would have to run a pipe about 10’ and drill through a cinderblock and brick wall. I can plumb the pipe if need but am not sure if it’s required.

I much appreciate your insights.

 

[frodo]

here is the deal on the T&P valves not being plumbed to the outside where you can see it
if it pops off in your basement, you will not know it till you go into your basement and look at it

I am pretty sure you see the outside of your house every day and would notice the T&P leaking with in 24 hours
if your T&P leaks in a humid basement for a week you are going to be real pissed off at the mold and smell that will happen
run the pan drain and the T&P outside like you are required to do

 

[justin_dewan90]

Listen to frodo. Run it outside. It's required by code.

 

[Diehard]

I would venture to say that the majority of T&P's discharges terminate above a basement floor. (Water heaters and boilers)

As far as code requirements...well that depends on the code.

Based on the UPC...
"Through an air gap into the drainage system or outside of the building..."

Based on the IPC... EDIT: Correction to distance above the basement floor.
It shall terminate not more than 6 inches above and not less than two times the discharge pipe diameter above the floor or flood level rim of the waste receptor or to the outdoors.

The important point, of course is that it would be readily seen.

 

[frodo]

I would venture to say that the majority of T&P's discharges terminate above a basement floor. (Water heaters and boilers)

As far as code requirements...well that depends on the code.

Based on the UPC...
"Through an air gap into the drainage system or outside of the building..."

Based on the IPC...
It can dump onto the basement floor with a 6" gap or to a waste receptor or to the outdoors.

The important point, of course is that it would be readily seen.

Bro Diehard,,

oh...hell here we go again..

 

[rdy4trvl]

wcodyd
What did you end up doing? I have the same situation (heat pump WH in crawl).

However, I do have another option - to run the T&P to the house's sewer main...but it's 28" above the base of the water heater...so technically it's >6" above the "floor".

And another question wcodyd - any issues operating the heat pump WH in the crawlspace?

Thanks

 

[Mitchell-DIY-Guy]

Put a condensate pump in for the condensate water, drain to daylight. (same deal as an a/c or condensing HVAC unit in a crawl space.

If you have a sump in the crawl space you can run a hose (radiator grade) from the T&P valve to that; else to outside. With all the water heaters in all the homes I've owned in many locations, only ONCE did the T&P go off, not because of a water heater problem (for which they are supposed to prevent the thing from blowing up) but because the T&P valve failed. Filled my cold garage with steamy water and vapor, looked like a steam room. So you just need to be on the safe side. It's not like a condensate drain which will be constant but small amounts of water. When those T&P valves pop--regardless of reason--you don't want to be around.

I'm fighting a situation in my new home here because of the local building practices where they don't "get" sealed crawlspaces or basements. It's a veritable swamp in my crawl, every joint on the HVAC is sweating, the air boxes and plenums sweat like marathon runners in July, the attachment points to the floor registers are sweating, literally dripping. Mold is growing on the joists, the trusses and around the floor registers--and this is a NEW house and the a/c has only been on for 2 months. Temp and humidity in the crawl is at the dew point. RH humidity down there is approaching 80%. There's a vapor barrier of sorts (plastic sheeting over dirt) but it's not sealed. It's an open crawl with vents. Local building codes and practices have not kept up with "best practices" which call for sealed crawls. This is the same group of people, builders and practices that think it's OK to place a tank style water heater in an attic. If the builder won't fix it I'll have to do it myself. Crawl spaces unsealed with dirt floors do nothing for a homeowner but cause trouble. Local inspector tried to blame it on the HVAC equipment but thankfully the HVAC Lennox techs came out and said nothing wrong on our end, it's the environment you made us put it in...

So, keep that water OUT of your crawl space no matter how dry it is now...

 

[rdy4trvl]

Put a condensate pump in for the condensate water, drain to daylight. (same deal as an a/c or condensing HVAC unit in a crawl space.

If you have a sump in the crawl space you can run a hose (radiator grade) from the T&P valve to that; else to outside. With all the water heaters in all the homes I've owned in many locations, only ONCE did the T&P go off, not because of a water heater problem (for which they are supposed to prevent the thing from blowing up) but because the T&P valve failed. Filled my cold garage with steamy water and vapor, looked like a steam room. So you just need to be on the safe side. It's not like a condensate drain which will be constant but small amounts of water. When those T&P valves pop--regardless of reason--you don't want to be around.

I'm fighting a situation in my new home here because of the local building practices where they don't "get" sealed crawlspaces or basements. It's a veritable swamp in my crawl, every joint on the HVAC is sweating, the air boxes and plenums sweat like marathon runners in July, the attachment points to the floor registers are sweating, literally dripping. Mold is growing on the joists, the trusses and around the floor registers--and this is a NEW house and the a/c has only been on for 2 months. Temp and humidity in the crawl is at the dew point. RH humidity down there is approaching 80%. There's a vapor barrier of sorts (plastic sheeting over dirt) but it's not sealed. It's an open crawl with vents. Local building codes and practices have not kept up with "best practices" which call for sealed crawls. This is the same group of people, builders and practices that think it's OK to place a tank style water heater in an attic. If the builder won't fix it I'll have to do it myself. Crawl spaces unsealed with dirt floors do nothing for a homeowner but cause trouble. Local inspector tried to blame it on the HVAC equipment but thankfully the HVAC Lennox techs came out and said nothing wrong on our end, it's the environment you made us put it in...

So, keep that water OUT of your crawl space no matter how dry it is now...

Thanks for the suggestions Mitchell. My "problem is minor compared to yours. I'm sure you've considered a dehumidifier (if you could get it sealed). The only thing I could suggest that's worked for me (pre-COVID) in a small town was to meet with the city building dept to the point they know me, my house, my issues, etc. Good luck...you have a few challenges there.

 

[Mitchell-DIY-Guy]

Thanks @rdy4trvl. Before I get any inspectors in here, I want to give the builder a chance to come clean and do the right thing.

These crawl spaces in humid climates are about the most dumb-a** things imaginable. The funny thing is, here in NC so many people are from "up north" like me, and we do BASEMENTS up north, which when done right (it's not even close to rocket science, it's the most elementary building with basic materials, easier than rough framing!!) are dry, clean, brightly lit, hold all the utilities in a very easy to work in space. Show me a plumber or electrician or HVAC tech that wouldn't prefer walking upright, in a clean dry brightly lit area to do his/her install or repair. Despite all these folks from up north, the local thought is "we don't do basements." No, instead of a basement with a steel beam (or new structural wood beams) and a few lally columns, I've got a crawl space with 46 (yes, forty six!) masonry piers in a 1400 square foot crawl space. Each with its own footing...but I digress...

I know the space needs to be sealed: that's best practices. I should have the walls insulated with Thermax 2" rigid foam board. The space needs to be dried out. At minimum I need a couple of small air inducers to pressurize the space by introducing a small amount of conditioned air. At max, I'll need a dehumidifier. Overall, I really need the builder to pay for it! If not, I'll be doing it myself as the contractors want astronomical amounts to do it.

 

[SHEPLMBR]

https://www.plumbingforums.com/thre...-for-heat-pump-water-heater.14207/post-107820Frodo has a point. How will you know if the T&P pops?

 

[Mitchell-DIY-Guy]

How would you ever know if a T&P valve pops? By putting it in a situation where you'll have a mess on your hands? I don't think that's the best solution.
Same with the self-draining catch pans underneath a water heater. If you have a minor leak, the water will just drain and unless you go looking periodically to see if all is OK, you won't know.

When I had the T&P valve pop/fail on me, that one time, we basically had no hot water--just warm at best. That triggered the look-see and I quickly found my garage had turned into a steam room.

Builders (not plumbers) love to spec hot water tanks in ATTICS here in NC. They have to have two drains to outside; a pan to catch a leak, and for the T&P. I dread the day my neighbors have to replace them...