Aquastat settings, warm start.

frankjc

Hi, I was wondering how to set my aquastat for "warm start". With the warmer weather coming, I was hoping to have the boiler not come on so often, and maintain a lower temperature.
Thank you.

STEVEusaPA

What type of equipment, what type of aquastat, what type of domestic how water-thankless coil, indirect, etc?

frankjc

Sorry. Oil fired boiler, tankless hot water, Honeywell l8148 aquastat. I have an electric hot water heater. The tankless coil is still connected, but not being used. I left it connected so that if the electric fails, I can open and close some valves and use it again.

STEVEusaPA

Best would be to replace it with a modern aquastat like the Carlin HydroLevel 3250. Then you can configure it with circulator hold off to protect the boiler, and program it like a cold start. Then if you need the coil, just a quick program change.
On your existing aquastat you can turn the low limit all the way down, or wait until heating season is over and turn the boiler off completely. If you do, check it after a day to make sure it isn't leaking between sections now that it's cold.

EdTheHeaterMan

The L8148 is a cold start control. The L8124 is the one that maintains boiler temperature. You may have the wrong cover on the correct control. (I have observed that before) If you are happy with the electric water heater and you actually have the L8124 control, you can set the LO dial to 120° then you can remove the blue wire indicated in the photo.

If you actually have the L8148 it looks like this and there is no adjustment for "warm start" only one dial for the high limit.

I hope this helps.

Ctoilman

You sure making hot water with electricity is less money than using oil?  Not even close in my area, Connecticut.

EdTheHeaterMan

Ctoilman said:

You sure making hot water with electricity is less money than using oil?  Not even close in my area, Connecticut.

In most cases, with new equipment, the tankless coil in the oil boiler will cost less to heat water than an electric water heater. There are those cases where the tankless coil was not properly maintained and there is insufficient hot water so a plumber gets called to solve the problem. Many plumbers are not familiar with the concept of maintaining a tankless coil so the "Go-To" remedy is a new Electric water heater.

Then some configuration of piping is used to "make the operating cost less" or "Just in case" and there are a series of tees and valves installed to confuse the whole thing. ...So if the electric water heater is working and the cost to operate is reasonable, you may not want to spend the $ to make it "Better". You may be disappointed with the result.

The only good way to get the oil heater to make efficient DHW is with an indirect. IMHO

frankjc

Mine is the aquastat in the first picture, i remembered the number incorrectly.
The electric water heater costs a lot more to operate than the tankless coil. I regret my decision every month when I pay the electric bill. The reason i went with the electric one instead of replacing the coil was mostly for more hot water capacity, I have a 2 person tub, and the whole 12 years I have lived there I have never been able to fill that tub, and have never been able to get a good hot shower. i was less nervous about installing the water heater myself than replacing the coil. I was convinced that I would snap the bolts that hold the coil in.

HVACNUT

You can repipe the tank like this for an Aquabooster 

frankjc

Sounds like a good idea, but the coil is so clogged barely any hot water comes out of it

HVACNUT

Then just set the low to 140° for summer.

Robert O'Brien

Eliminating idle loss to the greatest extent possible is key to an efficient oil fired system. This will allow that and provide copious hot water

gennady

Just install Taco I-series outdoor reset mixing valve. 2 or 3 way. https://www.tacocomfort.com/product/iseries-mixing-valves/

EdTheHeaterMan

So set the Low limit to 120° forever, remove the blue wire as I stated before. A wire nut on the end of the blue wire is important if the control is the older one without the insulated spade connector. This will convert your existing control to a cold start boiler and the circulator will operate whenever the boiler temperature is above 120°