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I had a different post a while back to figure out what boiler was best for my panel radiator system, I ended up going with the HTP pioneer based on simplicity, installation cost, and low maintenance. I am getting ready to have the system installed and had a couple questions about the best way to set this up. Right now I have an electric heat pump water heater because we didnt have a gas line in the house when we bought it. the water heater works fine, but 2 showers back to back can sometimes be a bit much for it, and I just added 2 new bathrooms in an addition we are building.
If I set the pioneer up just for heating it will run 140 supply at design conditions and use the onboard outdoor reset control. This should be pretty efficient. If I replace the heat pump water heater eventually with a conventional gas water heater i'd have 2 gas appliances running at the same time.
If I set the pioneer up to run an indirect tank, I'd have to store at 180 and have a outdoor reset mixing valve for the radiators. It will never condense, and be less efficient than the first setup. But, if I store at 180 and mix down, I'll be using less water.
Does anybody here use a similar setup to either of these? I'm wondering how much difference in efficiency i would see. I know I would never condense with the system storing at 180, but If i'm mixing and using less of the hot water that may make up for some of the decreased efficiency.
Maybe i'm overthinking this, but I dont want to do anything with the installation that i'll need to have changed down the road. I know there are other setups that might be a better fit (boiler with separate buffer and indirect tank) but the difference in installation, material and maintenance costs led me to where I am now.