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turn down boiler in summer when I only need hot water?

CalebCaleb Member Posts: 22
I have a burnhan set at 160 deg / 180 deg and its too hot for DHW. I just bought a Watts mixer to set the max temp at 120deg.. But can I turn down the system in the summer to reduce cycle time? What if I have separate gas DHW heater, or go on vacation for a week.. can I shut the boiler off completely?


  • icesailoricesailor Member Posts: 7,265
    Summer heat:

    Did some "expert" on some Internet Forum or TV How To show tell you that?

    They didn't explain that the control strategies of your boiler have your boiler operating at 160 degrees or lower. The 180 degrees are for your heating load. It only goes to 180 degrees if you turn up the thermostat. You can turn off the boiler when you aren't using hot water, but it is better for the boiler to remain hot. It keeps gaskets and seals from leaking as the metal contracts and expands. If you look really carefully, you might save a buck or two. It won't be worth it after the first time one of the gals in the house get into the shower and it gets cold because they forgot to turn the burner back on. That can be painful. A wet hen with wet soapy hair and going out.

    I'll see you later.
  • CalebCaleb Member Posts: 22
    edited June 2014
    no expert

    No "expert" told me anything, just my own logic thinking I don't need to maintain 160 deg throughout the summer.. I turned it down to 150/170 and it's working fine for now.. Want to get a monitor installed to see when it's cycling on and off while I'm not there
  • icesailoricesailor Member Posts: 7,265
    edited June 2014

    Get an El Cheapo electric clock cut the plug off, and wire it in through the burner motor. Set the clock for 12:00 O' Clock. Whenever the burner runs, the clock will run. Third World Clocking Device.  Just be sure that you keep a log book so you can remember when it runs more than 12 hours.

    You can set the "Low Limit/Operating control to anything you want. The lower you set it, the less hot water you have available.

    When you are done, you will find that your exercise in splitting pennies cost more in Sawzall blades than you saved in pennies.
  • icesailoricesailor Member Posts: 7,265
    edited June 2014
    Hot Water Tanks:

    No, you can heat water in a hot water storage tank using the tank less heater coil in the boiler.

    Which is the same as using a indirect coil inside a dedicated indirect heater tank. Except that a water heater tank used as a storage tank is a lot cheaper than a dedicated indirect heater tank.

    SS. DD.
  • icesailoricesailor Member Posts: 7,265
    Always too hot:

    Straight Tank less coils without  hot water extenders are always too hot. That's what the mixer is for. If he thinks his water is too hot when it first come out of the faucet, does it stay like that after 5 minutes? If it does, he need the extender replaced. If not, it will get a lot colder when he drops the boiler operating temperature down some more below 160 degrees.

    Want to kill the boiler quickly? Make it a cold start.

    As I understood the discussion, can you turn down the aquastat (that's set now for 180 degree High, 160 degree operating. If it's a tankless only, that's on the cusp. Lower and you get mad women and teenagers in the shower. Even with storage tanks. I set the Operating Control setting to 135 to 140 with a 20 degree differential because if I am going to clean it, I hate Kibbles & Bits with my very being.

    It matters not to me what is done. I'm not doing it and I'm not going to clean it.
  • icesailoricesailor Member Posts: 7,265
    Choir Director In Chief:

    You're preaching to the choir.

    If you have a boiler with an internal indirect coil (Tank-Less), why on earth would you want to disconnect it and buy an expensive water tank with a coil installed in it that you have to re-pipe the boiler and add a zone?

    I'd have to go looking, but someone used to make a big water boiler that looked like a big oil fired water heater. It ran at 12 PSI. It had this huge coil mounted in the front. No tank unless you installed one. Those suckers made some serious hot water. They were far better than a large Bock oil fired water heater because there was no corrosion on the heater side. The only thing the potable hot water touched was the inside of the coil.
  • icesailoricesailor Member Posts: 7,265
    edited June 2014
    You mean like:

    You mean like this?
  • icesailoricesailor Member Posts: 7,265
    edited June 2014
    Coil In Series?

    Look again Capt. Not in any way like you see it. If you shut off the power to the boiler, the tank will get cold and there is no other way to get it hot without turning it back on. There is no 240 volt power to any tank that I have ever done. Not either of those two, or any one I have ever done.  And although I won't say I've done hundreds of them. it is in a higher group of ten.

    HINT: The water heater isn't a separate heating zone. And it doesn't even have separate 120 volt power to the tank. And no other boiler controls except what it came from the factory with. The standard grade, El Cheapo Honeywell 8182 triple acting control or whatever the number is. I've always been numerically challenged. In my old age. it gets worse.

    I did a lot of electric heat conversions, got rid of the electric heat baseboard. I could sell the job because I would use the old, often new electric water heater as a storage tank. No indirect,  Replace the electric baseboard with #30 baseboard and you didn't need any carpenter work to replace baseboards. HW baseboards have more output than electric baseboards. Do just the first floor because you didn't have to go nuts getting pipes to the second floor. Use existing electric as back up, the first floor was heating the second, never had a complaint, and never have ripped out a tank because it didn't work.

    I've used the same piping scheme on places that needed more supplemental hot water or a place with a high output water heater that needed storage. Like a Bock 73E and a 120 gallon Rudd Commercial Storage Tank. That only needed the extra nuts for 3 hours in the evening. And it stops "stacking" of high output water heaters.

    Got a house with a 50 gallon gas water heater that works fine? Then, they add a jetted tub and they run out of hot water?  Add a 50 gallon electric water heater piped as a storage tank with the new tank as the draw tank and the old tank as the energy source. 100 gallons of stored hot water. Whatever the first hour draw on the gas water heater is, you just added 50+ gallons to it.

    That probably won't work for you. It always did for me.
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    sigh you know Ice is really good and smart right BC?

    The cord goes to the thermostat that controls the circulator pump. when the tank cools the circulator turns on and charges the tank. Please realise other people have good workable ideas that differ from what you think you know.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    Delta T

    That is the difference in temperature. If the boiler temperature is too close to the target temperature you will not make enough hot water to supply your home. Reducing the standby temp of the boiler can save fuel, yet it reduces the capacity to create hot water. A stand alone water heater may be a sensible answer for you, especially if you have a different fuel source such as natural gas.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    Tankless coils work just fine IF

    They are installed and piped properly. Aside from the cost of fuel oil being so high, they should always work. The one in my fathers own house that he installed new in 1971 gives a continuous flow of hot water until the boiler runs out of fuel. I can take an hour long hot shower at his house, get out do, do dishes, wash laundry, and have my kids shower without a cold shower. If your tankless is not providing this kind of hot water it is not working properly. Does it waste fuel, yes it does as you are warming the chimney all day long, but it does also make your boiler stay dry and it to not have the stress related to cold firing. So you burn fuel, not boilers. You need to decide which is more cost effective for you. I prefer a cold fired boiler with an indirect water heater. Ice prefers keeping the block warm. Both have their merits and faults.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • icesailoricesailor Member Posts: 7,265
    True DHW heaters:

    Those and all the others I have ever installed have been installed as true DHW heaters. They are piped like a prehistoric Brown Bros. Copper tank with a side arm heater in a gas burner or a Florence kerosene stove. The "tank Less" coil is the side arm heater. The only heaters I ever did were electric heat conversions where the electric water heater was already in place. The tanks are piped full size 3/4" nominal size on the hot and cold. There is full pressure in the hot and cold water supply. There is no potable water restriction through the tank less coil.

    I did indirect's. I did anything anyone wanted. I gave everyone lots of choices with prices. I'd have done Indirects if people were willing to pay more. I installed many water heaters like shown for people that didn't have enough hot water with a coil only and a 70A mixer. 40 years ago, they sold 30 gallon indirects (Aqua Boosters) for as much as I could sell the same electric water heater for a nice profit. The Aquabooster was just a standard 30 gallon gas water heater without the burner. The extra hole for the control is where you put the extra line to the coil. The instructions they showed didn't work well. I changed the way to make it a true side arm. It worked far better. With the concept, you can make any water heater a side arm heater for a bigger tank for more storage. Without the increased hourly BTU input. It has never once failed. Not EVER.
  • icesailoricesailor Member Posts: 7,265
    edited June 2014
    You're kidding?

    You're kidding?

    What do you think that I have been describing? How do you think I connect what I posted two examples?

    Did you miss the part about where I and someone said that the only electrical connection to the electric water heater might be a lamp cord to act as a switch leg through the bottom thermostat to the small Taco 006ST pump?

    When tank-less coils fail and do not produce hot water, if is ALMOST always from the inside of the coil becoming plaqued up from water hardness coming out of suspension in "hard" or water with high dissolved solids. Many of us who have been faced with this scenario pump a acid solution with a acid resisting pump through the INSIDE of the coil. Some of us even planned when installing a boiler with a tank-less in hard water areas to make provisions to do so for the future need to be de-scaled. Most of us have never taken a coil out of a boiler to clean the inside.

    Some of us have only seen a coil that is coated with calcium on the outside is from indirect coils where the coil is immersed in a tank of potable water high in dissolved solids and the hot high limit boiler water circulates INSIDE the coil. The heated water around the coil precipitates the dissolved solids onto the outside of the coil.

    The water inside a closed heating system becomes devoid of dissolved solids. Which are supposed to fall out of suspension into the bottom of the boiler where they stay for life.

    At least that has been my observation.
  • icesailoricesailor Member Posts: 7,265
    Nasty Water:

    You must have some kind of nasty water in your boilers. They must be steam boilers where you can't see the water level in the gauge glass. I have never in my life ever seen a coil in even an old and long running boiler that came close to your description. If you're talking tank less only boilers with no storage tanks, maybe you have a control issue. I think this all started with a controller setting. Maybe you just don't understand how the control strategies work. Maybe you have bad mixers or improperly installed ones. Maybe you were trying to save $$$ and set the limits too low. Either way, your experiences don't come close to what I have seen. If I spent the time to take a coil out of an active boiler, it would have only been to replace the coil because of a leaking red rubber gasket leaking and I was trying to save a boiler for someone that didn't have a lot of money to spring for a new boiler. Either way, I could have cleaned the black iron oxide residue off with some TSP and high water pressure from a hose.

    As far as cleaning coils, you hire someone else to do it? I don't hire anyone else. If they are lazy and don't know what they are doing, they are dangerous.

    I once cleaned a dirty (on the inside) coil that took me over 24 hours to clean. I left the full strength 40% Muriatic acid running overnight. The next morning, it was plugged solid. Nothing would pass. Even trying to run it backwards. So I hooked my air compressor to it and blew it backwards. Great big white chunks of calcium chips came out of the coil. About 2 cups worth. It was fine after that.

    One of the things about storage tanks is that as the coil loses performance, it just takes longer to fill the tank with hot water. The efficiency goes down but they sit idle most of a day so who cares. And they don't use anymore fuel running longer.

    But I guess you are right. You are far more educated than I am. I went to the University of "How does this work". with a Graduate Degree in "How Do I Fix It". A Post Graduate Degree in payment from satisfied customers who didn't wonder if they were being robbed. Like that late heater guy I used to follow. He wasn't a licensed plumber but he represented himself as one. He never saw a case of a lack of hot water that couldn't be resolved with a new boiler. He often sold the old boiler as a "Reconditioned" boiler. He never installed a 70A properly with a heat trap. "You don't need them".

    An "Old Timer" once told me that if they call you on the phone, they want to spend money. I'm going to send them to some fool that cleans coils and the sells them a boiler? Where I worked, I didn't have the luxury of sending them to a coil cleaning expert. Who would sell them a new boiler. I'll do that myself.

    I wonder if that's a reason why so many of us are so possessive about our customers. Especially the good ones who pay their bills and don't crab. I always gave them extra special care. Because they were special. Some still call me about problems that they can't seem to get resolved.
  • RobGRobG Member Posts: 1,850

    I also have had Ice's experiance with tankless coils. Now if you are talking about an indirect water heater the outside of the coil will get crudded up. It's the introduction of fresh water that calcifies. No boiler leaks=no calcification


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