TT PRESTIGE BOILER PE110 installed with Cast Iron Radiators

bob eck

Going through second heating season with a TT Prestige Excellence PE110 nat gas boiler. Great unit for heating and domestic hot water.

House has two floors with pleanty of cast iron radiators so boler is in condensing mode most of the time.

I have it piped primary secondary with grundfos Alpha pump pumping on low speed going up into 2" black supply and then out to radiators for both first and second floor.

Next summer looking at taking out 2" supply and return and building a 1 1/4" manifold for supply and return and running 1/2" Viega fostapex direct to each cast iron radiator and back. Each supply will have a ball valve to help balance the system. Will run first to second floor radiators and then first floor radiators and do first off supply last on return header to balance system.

By taking out the 2" balck steel supply and return piping will radiators heat up faster since the system will not have to heat all the water in the large 2" mains.

Would this make the system more efficent and use less fuel?

Paul Pollets

TRV's for best efficiency

You already have the Alpha pump, now replace the original radiator valves with thermostatic radiator valves (TRV's). Each radiator would be individually adjustable and the Alpha pump would modulate at lower speeds as the TRV's are set at lower temps.  The radiators would be balanced for the load.  The best of all possible worlds!!



Danfoss or Oventrop TRV's and valve bodies should be available locally.



The existing main could be kept, unless you want head height in the basement. I would insulate the piping with 3/4" wall neoprene.

TonyS

I would say no

If the 2 inch pipe is in conditioned space it acts as more radiation allowing the boiler to run at a lower temp for a given amount of BTU,s. I have also found that the 2 inch in the basement not only heats the basement but also the floor for the first floor which keeps your feet warmer and the stat lower. The 2 inch pipe usually shows the system was once gravity and that means it was piped 2 pipe direct return. You can reverse your return to even the flow or use the TRV,s. I would get rid of the primary/secondary and save some electric. Prestiges love single pump installs on large radiator systems.