No outdoor reset

Joel M

Since I cant afford an outdoor reset, I have tankless hot water system, dont want to pay for new system, I have lowered the settings on the aquastat by about 30 deg and still get great heat. The weather has been mild for the most part. When it gets real cold, I will raise the settings as needed. I am sure this is conserving oil and not a big deal to turn the dials. Does anyone else do this? Anyone know of any downside to doing this? Thanks!

johnnyd

gonna try that

...on a newly installed system with a seisco SH that sets from 95* - 130*. Running at 108* now, we'll see if it meets design (26K BTU/hr 80* delta) when it gets below zero outside.

The cheapest poor man's outdoor reset! Not to take anything away from the well-designed outdoor resets I read about on this forum, which will work much better without a compulsive DIY/designer (who never goes out of town on weekends) to fiddle with the supply temp.

Plumbob

sure

Sure, I did that on our CI boiler before we got rid of it. No reason for it to blast the house with 180 water for short intervals in moderate weather. We ran the aquastat down as low as it would go (140) and this resulted in more even heat although no noticeable savings.

hr

Is this

a cast iron boiler with a tankless coil? You need to make sure you do not run the boiler below @ 140° return temperatures. Extended runs below this temperature will cause flue gas condensation.

What did you set the operating aquastat to, and what is the on/off differental?

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Joel M

Yes, it is ci w/tankless coil. Set at 145/170 diff at 15.

DaveGateway

Just beware

that you might find the water going cold when a heating zone kicks in when the boiler is at it's low temp point and the cool water of the zone hits the boiler driving the temp down. The boiler could take over 20 minutes to recover back above 140° or so as BTU's are get sucked out by the tankless and heating zone.

Joel M

So you think this is not a good idea? I understand what you are saying, the 2 zones have setback thermostats, so for 8 hours at night they are not calling for heat at this time of year (set for 60*, it never drops that low overnight). Should I just put it back to 170/190?