On the western slope of the Cascades they don't crud up very quick at all- take that one off the checklist. ballvalve's "bottled water quality"== added minerals for fresh taste.
And if you run it at 110F instead of 140F, even in bottled-water country it can go decades without appreciable loss of performance, but not in TX. 140F would be a tank heater reference point, and you'll rarely need more than 110-112F out of the tap, so when it doubt, turn it down.
SFAIK recirc doesn't void the warranty on the TK3 as long as it meets their minimum pump sizing specs. (Scoll down to the discussion near the bottom of the page.)
The only thing in a typical home that needs fairly hot water is the dishwasher. But, at least some of them can heat their own water if the incoming water isn't hot enough. Without one or the other, the DW will not perform very well. same is true with a washing machine...many stains and things can be removed with cold water. But, should you need hot, some of them can heat the water, or will require greater than the nominal 110-degree water that may be fine for bathing. So, it really depends on what your needs and desires are.
No matter the water, life cycle testing shows the flow thru's to be a poor economic and maintenance choice.
But since it's already installed and working-mostly, fixing minor issues like this and getting the full lifecycle out of it is a better choice than just scrapping it (at least most of the time.) He's asking how to deal with it, not whether it makes sense to install one. TK3s will hang in there for a good long time in naturally-soft water country with fairly minimal maintenance, even if there's no "payback" in a financial sense on the somewhat higher efficiency.
Yep, that's my thinking as well. When it's shot, I'll pull it and go with a tank.
Originally Posted by Dana
If you have hydronic (pumped hot water heat), you'd be better off with an indirect tank running as special heating zone off the boiler than with a standalone gas-fired tank.
Unless lighting strikes and fries all of the controls on the TK-3 it could literally be decades before it's not worth fixing anymore though. They're neither as bad as the detractors make them out to be (or as great as their proponents.) Condensing tank hot water heaters can be pretty reliable- they're not nearly as complex under the hood.
I'm hoping you can help us. We just had our well replaced and are having problems with our tankless hot water heater. My husband has flushed it several times as we we clearing sediment from the lines. The first time he flushed it with vinegar, everything seemed fine. We were having problems with hot water pressure dropping throughout the house and he thought he would flush it again. He has had a hard time getting the heater to flush properly with the flow being restricted even during the flush. Any suggestions?