KA6 and DHW?

I'm glad to hear things are working good. Now for the lecture.

Tempering valves are for safety, and additional capacity if needed. If properly installed you get the best of both...non scalding water to showers and tubs, and untempered hot water to dishwasher and laundry. If you have children a safe water temperature is even more critical.

Good points, Rob. Youngest here is 14.

Another update:

After being out of town for several days, no hot water was used or flowed into the (turned off) Electric hot water heater, which is in series after our indirect hot water heater.

Although the I-HWH was at temp and not calling for heat, the first shower was too cold as the E-HWH had cooled off too much and was in effect tempering the incoming hot water from the I-HWH to a too low temp.

I had DD draw a tub of water at full-hot, while I turned on the E-HWH. Once the water reached hot temps and stayed there, we turned off the water, drained the tub, and DD was able to take a hot shower.

This confirms my concerns about just this problem and justifies the purchase of the 3-way stainless valve to select between series or bypass the E-HWH. Happily, it finally arrived and was waiting when we returned!

I haven't had a chance to install it yet, but will in the next few days, which should eliminate this problem

Note: I also ordered some stainless nipples so I could simply install using the existing flexible connection lines on each of the hot water heaters.

IMHO, this is DEFINITELY necessary in such a setup.

CoalisCoolxWarm wrote:This confirms my concerns about just this problem and justifies the purchase of the 3-way stainless valve to select between series or bypass the E-HWH.

I don't understand why the approach is to keep adding equipment that is not cheap when it was established a while ago from the measured flow rates that either the indirect or the coil could handle the DHW load. You are free to do what you want, but I hate to see people get the idea that a coal boiler with substantial real-time output and a big reservoir of hot water, like a KA-6, nevertheless needs an indirect, a storage tank and a fancy mixing valve to provide abundant DHW. It doesn't.

The last I saw a brand new coil from Keystoker was about $300, including a gasket. Most of the indirects I have seen that purport to have a production capacity of over 200 gph cost well over $1000, and that doesn't any of the substantial costs of materials and effort required for installation. For a little boiler with a minimal reserve, sure it probably could help. For a more capable boiler, my $0.02 is it adds complexity and cost where it frequently is not needed.

Mike

It doesn't make sense to me either. A tank full of cold water between the hot water source and point of use is going to be a problem regardless of your equipment choice at the fire end. Either take the electric tank out of the loop, or leave it turned on.

True, it doesn't need to be a complicated arrangement...

I have both electric and indirect...they are plumbed in parallel to the house hot and cold mains, not in series.

I don't run coal during warmer months, and this is the switch over procedure...Two valves, open one and close the other, reverse sequence the next time. The water in the next tank to go into service is allowed to heat up before the valves are switched.

http://www.waterheaterrescue.com/pages/WHRpages/E ... allel.html

The stainless 3 way valve will selectively bypass the electric HWH, which we will use when tending the stoker.

If/when we turn off stoker for...seasonal, vacation, repair or whatever...flip one valve and a breaker and we will have hot water again using the electric tank.

FYI. Already had the I-HWH plumbed into a zone from a few years ago, thought I was going to go solar

People can easily learn from my experiences- good, bad, cheap, expensive, whatever. I don't mind if people agree or not. I think fellow readers benefit from all parts of a discussion and project- I know I have