Water Heater PRV Discharge Line into Crawl Space?
Tom Pultz
14 years ago
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lazypup
14 years agoTom Pultz
14 years agoRelated Discussions
OK to Plumb Water Heater PRV Discharge Into Waste Pipe?
Comments (2)The preferred method is to run the line through the wall and discharge outside the structure. When discharging outside the structure the point of discharge must be at a clearly visible location and may not be obstructed by shrubbery or landscaping materials. When discharging outdoors the discharge end of the pipe MUST BE pointed downward. Under the International Residential Code the point of discharge must be within 6" of the average terrain ground level. Under the Uniform Plumbing Code the point of discharge must be greater than 6" but not more than 24" above average terrain. In a garage or unfinished basement the T&P line may discharge on the floor providing the said floor is equipped with a floor drain. When discharging on a floor the T&P line must extend from the output port of the valve to within 6" of the floor surface and the end of the line must direct the flow downward. When a gas water heater is installed in a basement where a T&P gravity flow drain line cannot be achieved the standard Temperature & Pressure Relief Valve (T&P) valve is to be removed and a WATTS 210 gas shutoff valve installed on the water heater vessel. A Pressure Relief valve is then installed on a hot water line at any convenient point above grade and a discharge line extended outdoors or to an approved indirect waste receptor. The T&P valve may be discharged into the house DWV system providing it is connected by means of an approved "indirect waste receptor" such as a utility sink or floor drain providing the lowest point of the discharge line must remain a minimum of 4 times the discharge line diameter or 2", whichever is greater, above the flood level rim of the receptor. A T&P discharge line SHALL NOT discharge into a water heater drip pan. The T&P discharge line diameter must be equal to or greater than the diameter of the discharge port. If the total developed length of the T&P discharge line exceeds 40 feet, the line size must be increased by one nominal trade size. All horizontal runs of the discharge line must be pitched at 1/4" per foot towards the discharge end. There shall be no traps or valves on the discharge line and the discharge end of the line SHALL NOT be threaded. (If run with galvanized iron pipe the threads must be cut off the end of the line)....See MoreNeed advice on putting water heaters in the crawl space
Comments (3)An interesting idea, but, for the reasons you have identified, it could be something you come to regret. It just seems like a lot of work and expense for something with modest benefits. In my view, it would be a pain to have them located in a crawl space where they won't be as easily observable for leaks, etc., so you'll have to remember to crawl in there to do regular inspections. Further, installation now and any future maintenance and/or changeout in a space like that would not be fun....See MoreWater Pipes Freeze in crawl space
Comments (5)"One thing i can tell you that apply's universaly,copper pipe is best for preventing freezeing. Reason is because heat travels through copper better than iron,plastic/pvc doesn't conduct heat at all." This is 180 degrees wrong. Right facts, wrong conclusion. Heat (of anything) travels from hot to cold. Copper is an excellent conductor of heat (also electricity), so water in a copper pipe will lose its heat (that's what getting colder is) to cold air faster than water in a pipe that isn't as good a conductor of heat. PEX pipe expands and doesn't break when subjected to freezing temps and will return to its original shape when it thaws. One has to be careful to use connections that won't give way under the freezing. A good plumber experienced with PEX connections should be able to fix the problem....See MoreHeath Pump Water Heater (HPWH) vented to conditioned crawl space?
Comments (6)Wise questions and encourage you to carve out the proper space for the HPWH. Most experts are not going to be ok with the pantry-door-open approach though it would probably perform fine if you actually left it open all the time. For noise, expect something like loud fridge. Plenty loud for most people to keep the pantry door closed, which could lead to problems. Yes, air in a room will be cooler and drier with HPWH, the smaller the more noticeable. I think AirTap's model is the only one that can be ducted at this time and don't know anything else about that brand. A smaller closet could work with homework and good HVAC craftsmanship. Conditioned crawlspaces and basements are ideal locations for HPWH. I feel if topography is suitable for a crawlspace, then you are approaching headroom necessary for HPWH. You could maybe dig an extra couple feet to create a pit for the appliance but would ensure the depression has adequate daylight drainage provisions. The extra cost of this work could be balanced by skipping the dehumidification needed for most basements and crawlspaces but it still might not be enough to totally eliminate conditioning needs. Electric demand water heaters can make sense in some situations but I don't think 23' is going to warrant them. You might be better off finding a plumber well versed in smart distribution design. I think homeruns (and close-to) of 3/8" or 1/2" tubing would be better in most situations. For those still in design stage, consider making small plumbing footprints a top priority....See Morelazypup
14 years agoscrew_code_com
13 years agobrickeyee
13 years agoTom Pultz
13 years ago
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