Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Removal of tankless coil from boiler

Options
Jmacd7800
Jmacd7800 Member Posts: 9
I just had a plumber re-route my domestic hot water from boiler tankless coil to an electric heater. Is there anything I need to do with the boiler now? It has 3 zones for heating my house that. Thank you 

Comments

  • pecmsg
    pecmsg Member Posts: 4,882
    Options
    Why electric?
    What did the plumber do to the old water heater?
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    Oil is too expensive to heat hot water. And ther was no old water heater, domestic hot water was heated with tankless coil in boiler 
    STEVEusaPA
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,044
    edited October 2023
    Options
    The control that operated the oil burner does not know that you disconnected the water heater. The control will still make hot water you can't get to because the pipes are disconnected.

    Now you want to make the boiler a "heating only" boiler. What control is making the burner and circulator operate? It is the control that the thermostat wire from the zone valves is going to

    Maybe a L8184?
    Pictures with the cover off will help

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Jamie Hall
    Jamie Hall Member Posts: 23,426
    Options
    Jmacd7800 said:

    Oil is too expensive to heat hot water. And ther was no old water heater, domestic hot water was heated with tankless coil in boiler 

    Not around here it isn't. Electricity is about three times as expensive per gallon of hot water... but your mileage may differ.

    As to the boiler, you or someone needs to change it to cold start, which involves mostly resetting the aquastat (or possibly replacing it). Leave the old coil in place in the boiler -- it will do no harm. However, do NOT cap the old pipes.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    STEVEusaPAmattmia2kcopp
  • ethicalpaul
    ethicalpaul Member Posts: 5,723
    Options
    > Electricity is about three times as expensive per gallon of hot water

    Yes, if you only had to heat one gallon. But he has to heat his entire boiler plus all the water in it just to wash his hands. It's outlandish, especially in the summer.

    Even a resistive electric water heater run for only a few bucks per day.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • pecmsg
    pecmsg Member Posts: 4,882
    Options
    Jmacd7800 said:
    Oil is too expensive to heat hot water. And ther was no old water heater, domestic hot water was heated with tankless coil in boiler 
    Wait until you see the electric bill!

    Why didn’t the plumber take care of the old tankless?

    Look into heat pump water heaters if you insist on going this route. 
  • HVACNUT
    HVACNUT Member Posts: 5,860
    Options
    What's done is done.
    What model aquastat is on the boiler, L8124? L4081B?
    Turn the Lo as low as it goes. You can also McGuyver you're triple to make it cold start, if that's what you have, or invest in a boiler control with a plethora of options as opposed to just n aquastat. 
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    HVACNUT said:
    What's done is done.
    What model aquastat is on the boiler, L8124? L4081B?
    Turn the Lo as low as it goes. You can also McGuyver your triple to make it cold start, if that's what you have, or invest in a boiler control with a plethora of options as opposed to just n aquastat.


    Here is what I have. Can this be turned into cold start for heating only?

  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    The control that operated the oil burner does not know that you disconnected the water heater. The control will still make hot water you can't get to because the pipes are disconnected. Now you want to make the boiler a "heating only" boiler. What control is making the burner and circulator operate? It is the control that the thermostat wire from the zone valves is going to Maybe a L8184? Pictures with the cover off will help

  • mattmia2
    mattmia2 Member Posts: 9,734
    Options
    Turn the knob that says lo as low as it goes, as far clockwise as it goes. The way it is now you are burning as much oil as the oil you were burning before that wasn't making hot water.
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    mattmia2 said:
    Turn the knob that says lo as low as it goes, as far clockwise as it goes. The way it is now you are burning as much oil as the oil you were burning before that wasn't making hot water.
    I have the boiler completely shut off via the disconnect now. Wanted to show how I had it set before the coil was disconnected. Thanks though! 
  • mattmia2
    mattmia2 Member Posts: 9,734
    Options
    it will still waste the same oil it was wasting before when you have it on for heating unless you set it to cold start.
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    That’s what I’m trying to figure out how to do, wondering if I can do it with current aqua stat I posted pics of. 
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    pecmsg said:
    Jmacd7800 said:
    Oil is too expensive to heat hot water. And ther was no old water heater, domestic hot water was heated with tankless coil in boiler 
    Wait until you see the electric bill!

    Why didn’t the plumber take care of the old tankless?

    Look into heat pump water heaters if you insist on going this route. 
    Have used half a tank of oil since May at $1.65 per litre current price just for hot water. Electric won’t be this much. 
  • mattmia2
    mattmia2 Member Posts: 9,734
    Options
    Jmacd7800 said:

    That’s what I’m trying to figure out how to do, wondering if I can do it with current aqua stat I posted pics of. 

    turn the knob that says lo to the lowest setting. if that setting is below the temp of the room it won't fire. that knob says keep the boiler at this temp when there is no call for heat.
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    mattmia2 said:
    That’s what I’m trying to figure out how to do, wondering if I can do it with current aqua stat I posted pics of. 
    turn the knob that says lo to the lowest setting. if that setting is below the temp of the room it won't fire. that knob says keep the boiler at this temp when there is no call for heat.
    Not sure I understand. The room temp will never be higher than 120F so the lo setting of 120 will be higher than room temp. 
  • mattmia2
    mattmia2 Member Posts: 9,734
    Options
    it goes a bit below 120 but it might still try to keep it at say 100. i can't find good instructions for that so someone who knows that triple aquastat will have to comment. i think there is something with a jumper removal that can make it cold start too.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,044
    Options
    You can make this a cold start boiler very easy.


    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    mattmia2kcoppMikeAmann
  • Jmacd7800
    Jmacd7800 Member Posts: 9
    Options
    You can make this a cold start boiler very easy.
    Thank you! So to give whole story. This boiler had tankless coil for hot water and 3 zones for heating the 3 floors of my house. Tankless coil disconnected and now hot water through electric tank. Plan to use the boiler on only 1/3 zones primarily as I have heat pumps on other 2 zones. Changing the wiring as you showed above will do this and will this be ok? 
  • MikeAmann
    MikeAmann Member Posts: 998
    Options
    Pulling the blue wire out of the white block disables the LO limit for keeping the former tankless coil warm, but you do retain circulator control via the control knob. Now you are able to use that LO limit control for setting the temperature that the heating circulator turns on and off. Watch out for too low return water temperatures.
    Jmacd7800