condensing high eff. gas fired boiler with cast iron rads

Brad White_198

As Mike said, CI and condensing boilers are a great match.

Those who say that "return temperatures will be too high", do not understand that ANY system can have that condition. It all depends on your flow rate, initial temperature, heat loss and the size of the radiator relative to that heat loss.

If your building has over-sized radiators relative to heat loss (the year, 1919, is borderline for "open window" heating capacities consequent in response to the Influenza Epidemic), you are even better positioned.

TT makes a very good value boiler and very reliable from all I have heard. Thermostatic radiator valves (TRVs) on the radiators are a good technique to fine-tune user comfort.

Rob Stannier

condensing high eff. gas fired boiler with cast iron rads

I'm afraid we have gone ahead and signed the contract but.... can any of you tell me if mating a Triangle Tube high efficiency gas boiler to an old hot water rad system is going to make for fuel efficiency? I have heard rumblings on some blogs about return water temp from base board rads being too high for these condensing boilers but our rads are the really old, heavy, cast iron ones and are very large. We must replace our old 1919 cast iron boiler which has served faithfully all these years but, along with the gas conversion burner, was at the end of its life. Our installer is very reputable and seems to feel Triangle Tube Solo 399 is right for us. We are an 8 plex apt building so we are talking about 10 or so rads in each apartment. We are also worried about the venting out the side of the building. Our chimney is too narrow for the necessary liner for the number of BTU's. We have been told there will be some icing problems near the vent in winter but what about smell, noise etc. Thanks for any reassurances or caveats.

[Deleted User]

Great purchase

Triangle tube seems to have a loyal following with great feedback. Cast iron rads and a mod/con boiler will work great together.
Make sure the boiler is piped primary/ secondary per manufacturers recomendations. I would utilize a low loss header for an application like this if it is in the budget. A low loos header will help with air and dirt elimination. If no low loss header make sure a wye strainer is installed on the reurn side of the heating system it will help eliminate and rust or iron from entering the boilers heat exchanger.
Good luck

Rob Stannier

condensing high eff. gas fired boiler with cast iron rads

Thank you both, Mike and Brad, very much for this. I will copy your advice and ask the installer about the low loss header, the TRVs and following manufacturers instructions to the letter. I was very interested in the 1919 Epidemic history. I will keep the website posted on what happens with the new system.

Ross_7

Make sure you see ....

a copy of the heat loss from the contractor, to make sure that the boiler is sized correctly for the application. Good luck!
Ross