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boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 1:22 pm
by lincolnmania
i'm getting a efm 350 with a domestic coil soon and i'm trying to get a better idea of what i need to do to switch over from the electric water heater.
i know i need a tempering valve (or a globe valve) so no one gets scalded.
is the water coming thru the coil enough for my house? it's just 2 of us, 2 bathrooms, laundry, kitchen sink, dishwasher.
i have well water if that means anything, the storage tank is in the basement.

do i want to store 50 gallons of hot water in the water heater tank? i do plan on keeping it for backup. i do have a new stainless steel circulator pump that i had bought for a project (was going to put a coil in my coal stove until i read how short lived they are inside the stove)

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 2:37 pm
by gaw
No storage tank needed, you should never run out of hot water.
Tempering valve is good to have but not necessary, mine is still in a box on the shelf ( good intentions) but I grew up in s house with the same extremely hot water. You get used to it quick.

So a quick cheap setup would just be to plumb the hot outlet from the coil into the hot water line of the house. You can plumb in a hot water heater bypass.

Hard water will shorten the life of your coil in the boiler. Get a softner if needed.

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 3:29 pm
by leward
I have a 520 with coil. I also have an electric HW tank. I do not run boiler in summer however. I did install a tempering valve and a couple of tees and valves in the HW lines. Once boiler is running for the year I feed the electric tank with hot water from the domestic coil on the boiler. I have it set for around 120F ( electric almost never kicks on )
Once I shut the boiler down, I turn two valves and feed the electric tank conventionally for the summer HW needs. I agree you would almost never run low on HW with the 350 & coil, but you would have to run it year round for your HW supply -- though not necessarily a bad thing

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 3:31 pm
by lincolnmania
will an electronic water softener work?
i do not want to add salt to the water, my mom has stage 4 kidney disease.

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 3:34 pm
by lincolnmania

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 3:50 pm
by gaw
lincolnmania wrote:
Tue. Jan. 07, 2020 3:31 pm
will an electronic water softener work?
i do not want to add salt to the water, my mom has stage 4 kidney disease.
No.

If you have enough calcium in your water you need a regular ion exchanger to do the job. Maybe you're water isn't that bad as is, test it. Hard water will eventually block the coil but it takes years. The more calcium the faster it will block. If you're worried about the salt roll the dice and go without. If you use the hot water heater for a storage tank you may never notice a problem. I did have my coil on the old oil fired boiler block completely for me with the water I have. :o

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 4:08 pm
by lincolnmania
i know we have hard water. the original galvanized plumbing i ripped out almost 30 years ago was pretty caked up. i replaced everything with cpvc when dad and i built the addition in 91. nothing sticks to the cpvc.
my grandparents lived up the street and so did my great aunt and uncle, they had water softeners. my dad did not want a water softener.

i'm not sure what the efm domestic coils cost to replace, i have seen videos on descaling them.

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 4:27 pm
by europachris
My water is 30+ grains per gallon, plus a hefty dose of iron. Out of the tap it is almost undrinkable - tastes like you're eating an iron skillet. I run it through both an iron filter and a softener. Clothes last longer, water heaters last longer, dishwashers last longer (and clean better), etc. etc. I can't imagine not having conditioned water.

That said, I don't drink it because the harder the water, the more sodium ions are needed to replace the calcium and magnesium. The total amount of "junk" in the water doesn't change, only the "type" of junk that is in there. So, I installed a simple reverse osmosis system for drinking water as well as to supply my aquarium. The R.O. unit is fed softened water which greatly extends the life of the membrane and filters. I needed a small booster pump to increase the incoming pressure from the well's 30-50 psi to about 90 psi for best efficiency of the R.O. unit (gallons produced vs. gallons to waste).

In my case, the cost of a softener, salt and the added R.O. system is far outweighed by the savings of longer lasting equipment and not having every faucet, sink, tub, shower and toilet clogged with minerals and as red as a Mesabi iron mine.

Have your water tested and see what it really is. If it's harder than 10 or 12 grains per gallon, a softener is beneficial. If you have liquid concrete like me, it's mandatory.

Re: boiler domestic water questions.

Posted: Tue. Jan. 07, 2020 4:36 pm
by franpipeman
pipie you coil with unions ,isolation valves and drains with hose thread to acid clean the coil on occasion.

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 8:49 am
by Kungur
We have a Keystoker KA2 and here is my setup. I insta small circ pum at the thot water drain and pump to the coil. It returns back at the top of the tank. I also have a cheap timer to cycle the pump at different times. I do have a tempering valve as it seems to be very hot in the shower! This is an electric water heater.
I do also have it setup to be able to delime the coil which I do yearly.

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 9:10 am
by Pacowy
Using a tank and recirc pump with the coil may be necessary with a smaller boiler like a KA-2, but seems unlikely to be needed with an EFM 350 under the circumstances described.

Mike

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 9:30 am
by lincolnmania
thanks for the advice.
sounds like i need to plumb the hot water heater so that it can be bypassed when not in use and plumb the coil so it can be isolated to be descaled.
should the electric water heater be drained when not in use?

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 9:41 am
by CapeCoaler
Nasties grow at less than 140*...
Drain it or add bleach...

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 9:54 am
by lincolnmania
how much copper pipe should i run out the coil before switching back to plastic pipe? i am assuming not a good idea to plumb out of the coil with pex due to boiler temps? my water pressure is 50 psi after the pump has just run.
i think i am going to do upgrades in pex pipe and replace the cpvc in sections as needed.

Re: boiler domestic water questions.

Posted: Thu. Jan. 09, 2020 9:54 am
by McGiever
Curious, Who here bypasses their HWHT?