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Reversing flow of single pipe loop
I have a simple question but I will explain my situation first so everyone can see where I coming from.
I live in Maine, me and my wife purchased a house that was built in 1992, it has a 2 zone single loop fin tube baseboard heat that was common for the time. Hot water was provided by a Thermal Dynamics boiler listed at 85k. Upon inspection it was determined the boiler needed to go, it was 25 years old, had blown the DHW coil gasket and had pressure issues because the coil had pin holes in it.
At some point in 2004 they added a 20 x 20 foot addition to the house and just extended the first floor zone.
The thermostat for the 1st floor in in the living room.
No natural gas and only heating oil in my area so we went with a Utica Trifire boiler with a Utica indirect tank, kept the existing zones and added a third for the indirect. Zone valves are the original Taco 571's, the tank doesn't have a zone valve it only has a Taco 007e pump. The controller is a Taco Zone Control. The house heat is pumped by a Taco Viridian Delta T pump. Both pumps are pumping away from the boiler after the expansion tank.
The first problem we had was the boiler was short cycling and using a lot of oil. We reduced the nozzle from the stock .85 to the recomended by Utica .65. We also changed the Delta T from 20 to 15 in the pump settings per Taco. The short cycling stopped and the high fuel consumption stopped as well.
Last week twice the boiler shuddered like is was misfiring. Our tech came out and replaced the nozzle and double check ed all the settings and fittings and found the pump pressure was lower than it should have been and the feed line was loose. It hasn't shuddered since.
Our biggest problem which the old boiler suffered from as does the new one is the heat in the living room where the thermostat is doesn't really seem to heat like it should. The living room is the last radiator in the loop, the addition they added is basically in the middle of the loop and probably has 3 more feet of radiator than it should, it is also the hottest room in the house. When I put the thermo gauge on the radiators there is right about 20 diff between what is coming out of the addition radiator and the living room radiator. I also did a heat loss calculation using the Slantfin app and boiler size was right about 58k.
My question is can I flip the connections on the loop, make the living room the first on the loop? It's a pretty simple connection and not far apart. I can hook up what used to be the return for that zone to the supply from the boiler just after the ZV and then hook up the return to the boiler to what used to be the supply. The loop will just feed in reverse.
Sorry for the long post. Just trying to explain everything as best as I can so you can make an informed decision.