oceanjunkie
New Member
I have a 30yr old peerless oil fired boiler, single zone hydronic heat, 5gpm tankless coil setup in NY. We've been in the house for 2 yrs now and so far so good. We are looking into adding a 30-40 gallon indirect in order to improve the efficiency of our system. I having trouble getting answers to a couple questions I have.....
-It seems that an indirect should save about 20% on oil compared to the tankless. I'm estimating that over the past 2 years we used about 350 gallons/yr of oil for DHW. So the indirect might cut that down by 70 gallons? From actual experience does this sound high or low?
-The contractor said that we'll use the same aquastat that's currently installed in the tankless coil to control the boiler temp. It just has a hi & lo setting. I read that the indirect temp setting should be at 140F to prevent bacteria....so doesn't that mean that I have to keep the boiler's aquastat at a minimum of 140 on the LO side? Right now I run 150/120F on the aquastat until the weather outside really drops, then it's at 180/155. If I have to keep the boiler at a higher temp all year round, wouldn't this negate the benefits of the indirect?
-The plan is to leave the tankless in place and add valves so that it could be shut down but available in case we needed it. Sounds like shutting both the inlet & outlet is a bad idea....so if we close off the outlet and leave the inlet open we're okay?
Thanks in advance for your replies....
-It seems that an indirect should save about 20% on oil compared to the tankless. I'm estimating that over the past 2 years we used about 350 gallons/yr of oil for DHW. So the indirect might cut that down by 70 gallons? From actual experience does this sound high or low?
-The contractor said that we'll use the same aquastat that's currently installed in the tankless coil to control the boiler temp. It just has a hi & lo setting. I read that the indirect temp setting should be at 140F to prevent bacteria....so doesn't that mean that I have to keep the boiler's aquastat at a minimum of 140 on the LO side? Right now I run 150/120F on the aquastat until the weather outside really drops, then it's at 180/155. If I have to keep the boiler at a higher temp all year round, wouldn't this negate the benefits of the indirect?
-The plan is to leave the tankless in place and add valves so that it could be shut down but available in case we needed it. Sounds like shutting both the inlet & outlet is a bad idea....so if we close off the outlet and leave the inlet open we're okay?
Thanks in advance for your replies....