Replacing Baseboard with Radiators
need to rip out the inefficient copper tube and fin baseboard convectors and replace them with a nice old fashioned cast iron radiator for the ground floor in my 3 story brick townhouse. Right now the only thing heating the ground floor is the boiler which makes it about 8-10 degrees colder than the rest…
need to rip out the inefficient copper tube and fin baseboard convectors and replace them with a nice old fashioned cast iron radiator for the ground floor in my 3 story brick townhouse. Right now the only thing heating the ground floor is the boiler which makes it about 8-10 degrees colder than the rest of the house. The baseboard is on a separate zone of our hot water boiler supplied by copper pipe. Any plumbers that might do this job and what might it cost? I was thinking of doing it myself, but didn’t feel up to learning how to work with copper pipe, etc. myself just now. Also, don’t know what I would use to make the connection between copper pipe and the radiator at the end of its run.
I have a 1977 home which has a slantfin boiler in it. Recently I noticed that the system does not shut off. It used to. There are three zones, two are upstairs and one is in the basement. I checked the thermostats to see if they were shorted and they are not. what part on the boiler controller could be causing the system to continuously run. With all thermostats off it is still running. thanks in advance
You seem to have everything you need to have a warm house. You might be able to fix it at no cost.
I moved in to a 1911 Bungaloid near Chicago. It took me about four years to get the heat adjusted.
Year one: Remove/replace stuck valves on all radiators. Rebalance the system. The upstairs was still really cold.
Year two: Rewire the boiler control so that the pump was on all season, and the thermostat controlled the gas valve. (disconnect aquastat, install relay) Fiddle with the heat anticipator on the thermostat. Better.
Year three: Get fed up, and replace the thermostat with a new one. Better.
Year four: Realize how the thermostat sees the room it is in! The thermostat was in the dining room, which has one radiator, set full open. What would happen was, the boiler would turn on, the radiator in that room hould get warm, and the thermostat would “see” the warm radiator across the room, and shut off the gas! The system would never get all that warm, the upstairs was still cold, and the thermostat read exactly at the setpoint. (Raising the setpoint might have helped, but would be uncomfortable.) I set the dining room radiator to about 1/8 turn open (4 1/2 turns to full open). Now the radiators upstairs actually have warm water in them because the water temp has been allowed to come up. I set alot of the first floor radiators to maybe 1/2 turn open.
Understand this: The more open the radiator valve that faces the thermostat, the colder the rest of the house will be.
Try this:
Take notes as you go.
Wire your thermostat to control the fire. (OK, this might cost you a $20 relay)
Wire all the pumps to be constantly on. (My 1/12 hp pump costs me 60 watts or so. $5/month.)
Set all the convectors in the first floor to be fully open. Set all the radiators to be about 1/4 open.
Run the system for several hours. Your boiler temp. should be much hotter.
Is the first floor warm enough? No, then turn down the radiator in the room that the thermostat is in.
Check the other rooms for comfort. You might want the bathrooms warmer for example. We like our bedrooms cool. Adjust as necessary.
Adjust the anticipator to achieve the burner cycle time recommended in the boiler instructions.
Write down the final valve settings, in case some four year old monkeys with them.
The only good reason to zone a system is if the heat demands are different at the same time. If you want to heat the whole space all at once, you are good to go. If you want the basement cool while the upstairs is warm, you could try shutting off a pump, or shutting a valve.
After all this typing, I suspect the install worked OK at one time. No one would pay for such a malfunctioning install. Getting two temperatures out of one boiler can be done. It needs two pumps. You have two pumps. Look at http://www.thermoflo.com/Images/ Articles/CounterPointmixedup.pdf and check your piping.
I have a similar mix of copper fin/tube and cast iron, but only one pump. (Some previuous owner skipped the second pump, ran everything full tilt and probably had huge gas bills.) I live with it by shutting off the copper in the basement and putting a sweater on.
I am very interested in your final fix. I really think you have all the pieces you need. Please keep us informed.
As you suspect, your boiler is probably oversized by about 100%. Whatever. Too late now.
The issue you raise with boiler water short-circuiting through the first one or two radiators is common in a converted gravity system (which is likely a converted steam system). The only sure way to address that problem, if and when it appears, is to wire the boiler controls for constant pump circulation and have the thermostat simply activate the boiler’s burner.
Gravity systems are piped with very large pipes that contain a great deal of water. Having that water stop and start moving intermittently doesn’t allow for adequate heat transfer. Keeping the water moving at a constant and consistent rate of flow makes for good even heating and is likely to greatly increase system efficiency.
Good luck!
Thank you! I appreciate your input.
Yes, I have worried about the low temps of the water (starts at 100 degrees and goes to about 130-160) but feel that the cast-iron boiler (it’s gas-fired hotwater Slant Fin 100 series all over not steam) is probably hopelessly oversized. The system was originally gravity hotwater, then they added circulator pumps, I think. It has an input of 120,000 btu/h and the house is approx 1500 sq ft (not to mention that there is no appreciable heat output in the basement/ ground floor). I have also been insulating and weather stripping. Hence, I feel that upon installing radiators there, I would also require the boiler to heat the water to higher temps. There are only two runs of the convectors, and I plan on using most of the plumbing that runs to them for the radiators.
I have always wondered, separately, how radiators are balanced. i.e., how a radiator that is closer to the boiler does not short circuit the water back to the boiler instead of it flowing on to the boilers that are higher in the house. In this case, since the radiator (s) would be on a separate zone supplying only the ground floor that would probably not be an issue.
It does make sense and it’s NEVER a real good idea to mix cast-iron radiators with fin-tube convectors of any kind.
Your issue is primarily a balancing thing. You need to control the flow of water and energy (temperature) to two very different types of heat emitters.
Changing out the convectors is a probably the best move, albeit the most costly at this point.
Be careful with your water temperature. A cast iron boiler that’s making 140 degree water is prone to failure by producing a very corrosive condensate as a byproduct of low-temperature combustion gases.
If your boiler is not made of cast iron, you need not worry. The radiators will emit heat no matter what temperature the water inside them is…as long as that water is warmer than the room air temperature.
160-190 works well.
And just to be clear: Your entire building is heated with circulating hot water and not steam, right?
Thanks for your questions. Here’s what I think is the issue:
The hotwater boiler supplies about 6 cast iron radiators on the parlor and 2nd floors via the 1st zone. The temp of the boiler rises to about 140 degrees F on an average run which is sufficient to heat the radiators and turn off the thermostat which is at the parlor level. The 2nd zone circulator pump located in the basement/ ground floor switches on via an aquastat that is mounted on the copper outflow pipe of the 1st zone when the pipe/ water in the boiler reaches a certain temp (which can be set on the aquasatat). This second zone then supplies the baseboard copper tube/ fin convectors. Now, I have read elsewhere that these convectors require about 180 degrees to get hot enough so they can convect hot air to heat the room. Also, they tend to cool down almost as soon as the hot water stops running through them while the cast iron radiators on the upper floors continue to radiate heat and keep the thermostat from switching the boiler on. So even if I set the aquastat on zone 2 very low and the circulator pump running even continuously and ciculating water from the boiler through the copper tube convectors, the boiler water temp is too low for them and there is no appreciable release of hot air or heat from them. There is a second thermostat in the 2nd zone which can turn off the circulator pump, but the temperature requirement for that is never really satisfied because the room never heats up much. To me it seems like an issue of different water temp requirements for the radiators and the convectors which is why I was looking to replace them with a cast iron radiator like the rest of the house has. Also, I prefer the radiant heat of the radiator versus the hot air convected by the baseboard convectors, but at this point any kind of heat would be welcome in the ground floor. Does that make sense?
Sounds good – let me hear more!
mark
Can I ask exactly why you’re doing this work? What
I mean is, all radiators are 100% efficient. If you put a radiator in a room and fill it with BTUs of any source, the radiator will release that energy into the surrounding air until it is all the same temperature…in theory at least.
Is that too much information?
I’m just wondering if there isn’t a better approach to your heating problem. Are you sure that what’s existing can’t be made to work?
Consider thermostat location, pump size, enclosure restrictions, water temperature, etc. before tearing everything out.