Installation nightmare — how many problems can you spot?
The photo in Figure 1 is the inside portion of a heating system supplied by a non-pressurized outdoor wood-fired furnace. The two PEX tubes coming up from the floor through the 4-inch PVC sleeve lead back to the outdoor furnace. On the right of those tubes is a floor heating subsystem powered by a cast iron circulator. Mixing is provided by a thermostatic 3-way valve. To the left of this mixing valve is a bypass between the supply and return tubes coming in from the outdoor furnace — which has its own circulator. To the left of the vertical tubes is an “expansion zone” going to another floor heating circuit seen on the far left of the photo. For what it’s worth, this collection of hardware is installed in a multi-million dollar home.