I have a boiler used only for heating my house through baseboards. My hot water tank is a separate unit. For some reason the minimum temperature on the aquastat was set to ~160 even thought the boiler hets up to ~180-200 within 20-40 minutes from being OFF (depending on the outside temp). I feel almost as if the minimum can be turned off or at least down since we don't need the water to be immediately hot.I don't mind waiting a bit longer for the house to heat up if it will save me money! I'll just set my thermostat schedule to start 30-60 minutes sooner!Let me know if I'm missing something here.Boiler - Weil Mclain WGO-3Aquastat - GeniSys Model 7505
No just set your thermostat to where your comfortable. Having had a boiler before I know they take at least 1/2 an hour to get the water hot and circulating. You might get a thermostat that you can program to come on 1/2 hour before you get up these cold winter mornings. Once your house reaches the temp you want the furnace will shut down but the hot water will still circulate by the pump saving on the gas bill.
Yes, you need at least 140 degrees for cast iron boilers. Otherwise you may have condensation in the combustion chamber or heat exchanger. This can cause corrosion problems . Since this is a fairly new boiler, you need to call Weil Mclain and get their recommendations. You could take 20 years off it's life by running it too cold. The 140 degree minimum temperature comes right from Weil-McLain's service manual for the WGO-3 series, page 21. Here is a warning from ASHRAE about the dangers of running a non-condensing type boiler at a temperature below 130 degrees. Only certain types boilers can operate safely at this lower temperature. The ASHRAE document mentions this in several places: .....A 1 million BTU/hr boiler will produce 6 gallons/hr liquid water when fully condensing ???? This water will only condense at gas temp 135?F..... Any boiler can be a condensing boiler ???? Just return water cooler than 130°F ???? Water will condense somewhere in the boiler ???? Conventional boilers will be damaged ???? By corrosion or failed refractory from condensation ???? By sooting due to blocked fins (copper fin tube) ???? Condensing boilers are special ???? They can handle flue gas condensate safely ???? They can also run at non-condensing temperatures ???? Condensing boilers need special flue material ???? AL29-4C or PVC (316L is used in Europe)
