2nd floor zone

Tim in Yardley

I've recently removed the cast iron radiators on my 2nd level and replaced then with slant fin baseboard heating in order to gain more space in the bedrooms and bathrooms. I have a hot water boiler with 1 1/2" pipes that run from the 2nd and 3rd levels down through the floors to the basement where they expand to 2", then 3", then 4" before being reduced back to 1" copper into the boiler. The pipes from the radiators are all cast iron until they get to the copper at the near-boiler piping. The problem is that now I don't get a lot of heat on my 2nd level because the thermostat kicks off on the first level before my 2nd level is heated. The first level has huge cast iron radiators that heat really well.

I suspect I had an original gravity system that was converted to a circulating system. I have one large circulating pump on the inlet side of the boiler and I have no control valves. What I want to do is install one control valve for the main piping, but separate the 2nd and 3rd floors into their own zone and a 2nd control valve. I have one outlet pipe from the boiler that I would tee off of and install the two zone control valves. I have a few questions:

1) Since my circ pump is on the return side, I would just run a new supply system made of 1" copper in the basement and tap into each of the supply pipes that run up through the floor to the 2nd and 3rd levels. I would then leave the return piping the same as originally. Can I do that and will a 1" pipe be fine? The inlet and outlet of my boiler are 1".

2) Originally, I wanted to remove all the old cast iron piping to save on heating bills. Could I just replace that piping with all 1" copper piping in the basement and have two zones based off the 1" piping network? One for the 1st level and one for the 2nd / 3rd level? I do have wiring pulled to my 2nd level for the new thermostat.

3) My circulating pump is on the inlet (cold) return side of the boiler. Is that a problem? If it is, do I just move it to the outlet (hot) side of the boiler? It is a bit noisy when it kicks on.

Mike T., Swampeast MO

One of the worst things you can do to an old gravity system is replace radiators with fin baseboard.

The other certain way to mess them up is to replace the big main piping with smaller without completely re-sizing and re-engineering the entire system.

Some questions:

1) Is this copper fin baseboard? Perhaps you used Slant Fin Rhino Cast cast iron baseboard?

2) How did you size the new baseboard? Hopefully you didn't size based on its' output at 180° average water! With many old gravity systems you'll never approach 190° supply temp even in the coldest weather.

3) How did you pipe the new baseboards? Into the existing radiator supplies/returns in each room? In a single loop?

Scooter Libby

You're doing and planning to do a lot of work, but it doesn't look like you know what you are doing. You replaced the nice radiators with dinky baseboard, and now you don't get enough heat. Well, duh.

The likely problem (not necessarily the only problem) is that the upstairs now needs high head while downstairs is low head. However big your pump, water won't go upstairs if it can take the easy route via the downstairs. Zone valves don't appear to be the right way to deal with the problem because when they are both open, the upstairs still won't get any heat. A separate pump for the upstairs should help, but I haven't seen your system. As Mike T says, it is easy to throw the system out of whack if you haven't considered all factors.

Why do you think taking out the cast iron pipes will reduce your heating bills?

It makes no difference whether you're pumping on the hot side or the cold side, as long as you are pumping away from the expansion tank. The noise has nothing to do with hot side vs cold side. It's either a bad pump or it's badly mounted.

J.C.A._3

#1,Removing radiators to \"save space\"?

Un-founded in my opinion. When the radiators were there, you knew where NOT to place furniture. Now that you have installed baseboard, you have to keep the furniture away from it to get CONVECTION, which isn't as good a source of heat. In effect, you have made the space smaller.

#2. Trying to run radiators and baseboard from a single thermostat is a "battle of futility". Radiators have MASS!!!, and will hold the heat FAR longer than any copper finned baseboard will ever dream of.

#3. Separate those zones!! Piping is the least of your worries as long as there is a battle going on between a thermostat and a cold partner(s) in the rooms where they sleep.Trust me on this one...blankets aren't the answer!

Wherever you got the notion that baseboard would be more comfortable than radiators was but a passing dream, and/or nightmare...Time to wake up bud. Separate the 2 and live in comfort or you can use this as an excuse to scare yourself silly during the Halloween season.

Look to the left of "The Wall" and use the "find a pro" service. You'll be a hero when this is all done. J.C.A.