boiler outdoor reset for oil?
Hey guys I was in a supply house the other day and saw Honeywell makes an outdoor reset for oil boilers. I was wondering if any body has used them and how they work? I have a "newer" L7224/L7248 Aquastat I don't know if the outdoor reset would work with them or if I would need new aquastat
There are a bunch available form most control manufactures. Usually they are installed in series with the aquastat and the aquastat remains as a high limit.
The effectiveness of a reset depends on how the space is heated. Some convectors don't do well at lower water temps and have o be kept a bit higher. If the space is under radiated too. So maybe a bit of tweaking.
Overall there should be money saved.
Tracers work both ways.
lower water temps may also cause the boiler to condensate in the flue passageways. Combine water with sulfur and carbon deposits and you get acid and tar. Not what i'd want in my boiler. just sayin...
Nest is poo...
I agree tar and acid is not what I want. We have a cold start boiler and it gets turned off after every heating season, which kills me on start up again. I was just thinking that having an outdoor reset would be great to save some oil in the winter and in the summer keep the unit from running when theres no need to without shuting it down.
you misunderstand what outdoor reset does. it doesnt turn off the boiler, it adjusts water temperature based upon heating load and outdoor temperature. every time your boiler starts, unless it is an ancient POS, it is considered a cold start. yes, there is some warmth from the last time, but it is rarely at or near shutoff temperature of the aquastat.
my personal opinion is that it would save some oil but the maintenance costs/potential problems far outweigh the energy savings.
Nest is poo...
Boilers with tankless coils in them are not considered cold start boilers. Unless the tankless isn't be used anymore, and the aquastat has been rewired.
Originally Posted by HVAC_Marc
OD reset will shut the boiler off in summer.
At 3 bucks plus per gallon, a little extra work cleaning the boiler is worth the savings.
I understand what the OD reset does and my thinking is if I can keep the boiler switch on all the time and let the OD reset say hey its 70 degrees out and no need for us to make any hot water. It is a cold start boiler there is no coil hot water is off propane hot water heater.
With all due respect, and agreeing with beenthere, I don't think you understand OD reset. Without OD reset, if its a cold start boiler, and the thermostat is not calling for heat, the boiler wont (shouldn't) run. Unless you used to use it for hot water, and you still have a triple aquastat maintaining boiler temp.
OD reset, with WWSD (warm weather shut down), wired correctly would not allow the boiler to fire when the outdoor temp is above the WWSD target. Keep in mind, if the system is not completely intergrated, a thermostat could run the circulator, even though the WWSD wont allow the boiler to fire
Some other thoughts.
You should look into a product like Beckett's Heat manager.
If you still have a triple aquastat, you should consider maintaining temperature in the winter. Even 110 degrees will help, and not really waste too much oil.
If you could see inside two identical boilers, cold start after ONE heating season, and a boiler maintaining temperature after 3 seasons, the cold start will be a mess--kibbles and bits, etc., and the other boiler will just have some soot--easily brushed down. The cold start will have at least an inch of crud on the bottom of the chamber, due to condensation.
In the end I feel the cost of the 'extra' oil you use will be offset by the loss in efficiency of plugging up the exchanger with crud of the cold start.
Don't care for the Beckett heat manager. But thats besides the point.
Originally Posted by STEVEusaPA
A boiler that has been down fired, doesn't do well as a cold start boiler. They can become a mess quickly.
Originally Posted by wicat3
You can see if your L7224/L7248 Aquastat is Outdoor Reset Ready by looking at the label on the control. It should have the product number (example L7224U1002). After the product number there is another number running perpendicular that indicates the version (ex 1, 2, 3). Versions 2 and newer are compatible with both our wired and wireless AquaReset Outdoor Reset controls.
beenthere - Let me know if this response is non-compliant with forum rules. I don't want to cause any problems.
Honeywell ECC - Combustion
Last edited by beenthere; 11-22-2013 at 05:03 PM.
Reason: email address
Just saw that email addresses are not allowed. I apologize. Please remove it.
I think this is the manual.
I assume you want to install this on a residential boiler. My only thought is how big is the place? I can see this may be worth it on a large system or a commercial. But for a house? install a set back, above 50 turn boiler off, below, on. done, But that's what a thermostat does.