Removal of tankless coil from boiler

Jmacd7800

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 

pecmsg

Why electric?
What did the plumber do to the old water heater?

Jmacd7800

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 

EdTheHeaterMan

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

Jamie Hall

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.

ethicalpaul

> 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.

pecmsg

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

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

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

EdTheHeaterMan said:

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

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

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

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

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

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

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

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

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

You can make this a cold start boiler very easy.

Jmacd7800

EdTheHeaterMan said:

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

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.