Hi Guys,
Thanks for replying. I presently have 3/4" feeding the coil up until about a foot away than reduces to to 1/2", I have about a foot of 1/2" at the outlet of coil than it goes to 3/4". My basement bath has 1/2" feeding it and the other two baths (main floor and 2nd Floor) are fed by 3/4" reduced to 1/2" branches to fixtures. The coil does not presently have a tempering valve on it. I replaced coil approx 3 years ago and have recently cleaned it. I have plenty of hot water for all fixtures during non-heating months (apprx 6months here on LI) . During the heating months the shower never seems to get to a comfortable "hot" and hot water is really affected by the use of other fixtures. All fixtures other than showers have plenty of hot water. I do need to add a tempering valve and would like to add an electric hot water heater to it with a circ w/timer for the extra boost in the winter and in non heating months being able to turn the boiler temp settings down to 140 and let both work together For hot water demand. I was going to just add the tempering valve now (since it doesn’t have one) and see if anything improves this winter but, I may have to also replumb entire boiler because of small Leaks developing, scale, stuck check and a bad xtank. Going to use all new proball valves, circs with checks, taco sr504-4, etc. The boiler’s firebox and heat exchanger are in great shape. If I decide to go through with the replumb this winter I will then obviously add HWH now. My original question was asked because my thoughts were I would have more volume of water with a ¾” tempering valve vs. a ½” valve regardless of coil tap size. Would I keep the tempering valve on coil when adding HWH or just switch it to the HWH? (if ¾” valve is the way to go for coil) …Thanks again