Will switching to a lower temp prolong my water heater's life

[JustinH]

my tankless water heater is set to 120 degrees from the factory. That is pretty darn hot for a shower.

I don't think you need 140 for dishwasher, at least I don't and my dishes are clean. I use heated wash and heated dry as well.

 

[macarose]

My water heater was not keeping up. Put garden hose on it and drained alot of sludge from the bottom but it didn't seem to help. Went and bought a $3.99 dip tube and the water lasts for ever and is so hot it'll peel skin.

What is a dip tube? Thanks for the post above.

 

[Lubener]

If you haven't been flushing the sediment , don't start now . You run the risk of getting crud in the valve and it won't seal . Drip .. drip ..drip ..

There's a chance that the tank will spring a leak after draining 18 years worth of sediment. A leaky valve can be solved with a dollar screw on cap, no big deal.. Best thing is to continue the same practices that got that tank to last 18 years.

 

[BlueOvalFitter]

my tankless water heater is set to 120 degrees from the factory. That is pretty darn hot for a shower.

I don't think you need 140 for dishwasher, at least I don't and my dishes are clean. I use heated wash and heated dry as well.

Commercial dishwashers (restaurants, schools, etc.) must have a minimum of 180* hot water.

 

[macarose]

The water came out pretty clean this year and the flow is still good.

I used to do a complete drain with turning the water off, extinguishing the flame, opening the hot water faucet, and then use a cap with a hose attached to it to drain the remainder with a pail.

However it was an absolutely huge PITA to get the pilot ignited again. Every. Single. Time. So over the last several years I have just switched it onto vacation mode, drained about eight gallons from underneath a few times a year, and left everything else running as/is.

I don't really see any sediment. But part of me is thinking that maybe what I really need to do is go back to the old method and just buy a really long igniter.

I'm one of those guy who likes his home to operate like a Corolla. Keep everything low cost, invest in quality components, and make it all last forever (with a good spare in the garage just in case). I guess all of this is just first world problems. I don't think I'm damaging the water heater this way but if an expert tells me I am, then I'll change my ways.

 

[Wolf359]

After sleeping on this I think constantly changing the temp would be more stressful on the tank. Heating it up would cause some expansion while cooling would cause shrinkage, at least right now its trying to maintain a stable temp.

Actually it might be good for the thermostat. I've had lazy water heaters where the thermostat wasn't touched in a long time and it got stuck at a lower temperature. Playing with the temperature freed it up. At 18 years, the anode rod is probably gone. Here's a shot of an old anode rod and my new one. Got to it just in time.

 

[brianl703]

However it was an absolutely huge PITA to get the pilot ignited again. Every. Single. Time.

When this water heater inevitably springs a leak (hopefully not flooding your house) and you replace it, you'll be happy to know that the replacement will have a push-button spark ignitor to light the pilot light. This is because there's a flame shield around the burner. I think it's designed to keep the water heater from igniting flammable vapors.

 

[Wolf359]

my tankless water heater is set to 120 degrees from the factory. That is pretty darn hot for a shower.

I don't think you need 140 for dishwasher, at least I don't and my dishes are clean. I use heated wash and heated dry as well.

State sanitary code says no hotter than 130, I suppose you could do 135 or a tad above 130 as it's not supposed to be hotter than 130 coming out of the tap and it might cool a little between the tank and the tap. To prevent Legionnaires disease, you're supposed to be 140 or above.

I'm one of those guy who likes his home to operate like a Corolla. Keep everything low cost, invest in quality components, and make it all last forever (with a good spare in the garage just in case). I guess all of this is just first world problems. I don't think I'm damaging the water heater this way but if an expert tells me I am, then I'll change my ways.

As I've mentioned in many previous water heater threads, change the anode rod, if you're into cars and have an impact gun, it's not too bad. I did one set over a decade ago with just a 1/2 inch breaker bar and had to involve a 3 foot pipe and they were kind of a bear to get loose and was a 3 person job. Last time I did it, I got a Milwaukee 2767 and that just blasted them off, easy peasy one man job. I have 10+ water heaters and know that it works because I used to replace one every year or two as they rust out, now it's more like every 4-5 years or so.

 

[Lubener]

What is a dip tube? Thanks for the post above.

Probably not the dip tube. Many years ago there was a bad batch of them. They are plastic. They disintegrated and the pieces ended up getting lodged in the faucets causing problems.. Sediment is likely causing your tank to operate poorly.

 

[justfishing]

if you have gone 18 years without changing the anode and flushing there is no point to do it now. Flushing each year will get rid of the sediment and help with efficiency but at this point it may be holding you water heater together. The anode wears away to prevent your tank from wearing away. check it every year and to learn how much is left and if it needs replacing.

 

[Wolf359]

if you have gone 18 years without changing the anode and flushing there is no point to do it now. Flushing each year will get rid of the sediment and help with efficiency but at this point it may be holding you water heater together. The anode wears away to prevent your tank from wearing away. check it every year and to learn how much is left and if it needs replacing.

If the tank hasn't failed, it is never too late to change out the anode rod. The way the tank fails is that the tank rusts out. Once the anode is gone, the tank will start rusting next. The rod is only in the $20 range. If you go to the trouble of checking it, you would just replace it. The main problem with checking the anode rod is loosening the rod, if you have a high torque impact gun, it's not a big deal, but if not, it can be a real bear.