Spurt of Scalding Water with Touchless Faucet

[jmwillhite]

New house for us. Delta touch faucet (maybe 7-8 years old) in kitchen with an RO system under the sink. When we turn on the faucet by touch it *sometimes* gives a quick burst of scalding water then goes back to normal. I suspect it is the plumbing order. In the morning before the RO system has been used it doesn’t happen. Then once we use the RO and it is calling for water it seems to happen.

Cold supply line comes out of the floor, then check valve, then RO tee. Do you think the order is wrong? We had all kinds of issues (lukewarm showers, warm water from the RO spigot) that made me feel like a crazy housewife after we moved in. Replaced the check valves on both sides and that seemed to fix some of them. But still have this lingering issue. Thanks for any advice!

 

[Jeff H Young]

yes put the ro system upstream of check valve also could be issue with the faucet did faucet come with those checks or say you needed them ?

 

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[jmwillhite]

yes put the ro system upstream of check valve also could be issue with the faucet did faucet come with those checks or say you needed them ?

When we moved in we had a lot of weird issues like continually having to turn water temp up in the showers and warm water coming from the RO faucet. Check valves were in place. So I had new ones from Delta installed by a plumber because I didn’t think I could do it. I really am a housewife. I suspected that hot water was running into the cold side and vice versa. That did solve the problem in the showers. And we have not had warm water from the RO system since. But still having this burst of scalding water issue. My brain has constantly been trying to figure it out. And as I said, it only seems to happen when someone has recently used the RO faucet and it is calling for water to refill the tank.

 

[Jeff H Young]

When we moved in we had a lot of weird issues like continually having to turn water temp up in the showers and warm water coming from the RO faucet. Check valves were in place. So I had new ones from Delta installed by a plumber because I didn’t think I could do it. I really am a housewife. I suspected that hot water was running into the cold side and vice versa. That did solve the problem in the showers. And we have not had warm water from the RO system since. But still having this burst of scalding water issue. My brain has constantly been trying to figure it out. And as I said, it only seems to happen when someone has recently used the RO faucet and it is calling for water to refill the the tank.

cold and hot is mixing some how could be a bad check valve

 

[WorthFlorida]

The scalding hot water burst could be your water heater. I had it happen with my electric WH. One heating element burned out but the thermostat breaker did not trip. Water was getting inside the heating element and instantly turn to steam.

What type of WH do you have? The previous owner may have cranked up the temperature to max to overcome the other issues. As Jeff suggest, there is a mixing going on

 

[MikeinVirginia]

Coincidentally, I just moved into a new (to us) house with an 8 year old Delta touch faucet, and I'm having a similar issue (burst of scalding water).

We don't have check valves installed at all. I think what's going on is with the faucet on at the handle but off with touch, with the handles set for any mixture of hot and cold (not pure cold), the hot pushes into the cold (at least up to the check valve, which we don't have). So when the water is turned on with the solenoid (touch), you're getting hot water from both the hot and the cold until the "new" real cold pushes the hot out of the cold side.

In your case, my uninformed guess is that (assuming RO = reverse osmosis), with the check valve before the RO, your hot water pushes into the RO/cold side, and the RO filter/tank is a reservoir for that pushed hot water, until you turn it on and the cold flushes out that stored hot - until then, there's no mix, it's hot water from both sides (= scalding hot). So I would think the check valve needs to be after the T so the hot water can't push into the RO.

I'm going to add check valves to mine - hopefully the scalding issue will go away.

 

[jmwillhite]

cold and hot is mixing some how could be a bad check valve

Thanks. But we JUST had the check valves replaced with parts from Delta. I’m going to try and have them reorder the supply line. Really wish the plumber would solve this and not me with my guesses.

 

[Jeff H Young]

you need to be able to think it through a bit more for example , If you havent run your kitchen sink for awhile. put your hand on pipes and feel them is the cold water hot ? hot below the check valve or above? either you have to check it out or you hire someone we cant do the actual work here. other faucets or valves can be contributing as well the cartriges can be bad causing hot and cold mixing