cast iron vs. steel

kframe

Cast iron won't last 20 years?

BS.

The house I grew up in had a circa 1897 Weil-McLain steam coal boiler that had been converted to oil just after WW II.

It was still in perfect working order in 1981-82 when it was replaced for a much higher efficiency unit.

The hot water boiler in my Parents current house was installed around 1953, and it's also in perfect working order.

I know of dozens of 50+ year old cast iron boilers that are in perfect working condition.

Cast iron is a very durable material.

GP

Guys, thanks for all you help so far.

One more nugget of truth I want to know...

Is the whole issue of cast iron vs. steel as simple as I've been told by the contractors?

i.e. "Cast iron will last you no more than 20 years
Steel will out last you." (and I'm 33 right now. So that means I should expect 40-50 years out of a steel boiler?)

Thanks,
Gene.

Bill NTSG

Steel & Steam

Gene from your post below I assume you have steam? Other than commercial applications I am not currently aware of any steel steam boilers for residential currently being offered by any of the manufacturers [I could be way wrong] Installion , maintainence, water conditions, environment, all play a big part in how long any product will last. Steam and steel and oxygen corrosion right at the water line does not seem like a good combination to me.

Dennis - Reliable Services

steel

boilers, especially oil fired models need to be cleaned every year, return water temp is critical to low and the condensation that will form in the tubes will rust those baffes in place. Years ago I brought a two year old boiler that we could not get the baffles out of back to the shop, I used a sledge hammer and a 1' pipe nipple, I could not drive the baffle through its tube. This customer would not agree that steel is better. By the way I have removed cast boilers that were not leaking, that were close to 100 years old. I have never seen a steel boiler that is pre 1940 in any house (I've only been doing this for 25 years).

John@Reliable_2

Gene, I think you have it backwards!

I replace 50+ year old cast iron boilers all the time. And I also replace 20 year old steel boilers all the time. As far as nipples I do like them to be the same material as the boiler so they both expand at the same rate.I have one boiler that I service which is over 60 yrs old and has a hole sealed with expoxy and a bolt on the mud drum for the last 5 yrs, try that w/ a steel boiler. John@Reliable

GP

Right, it's a commerical app. We've currently got a Kewanee 3mil BTU steel boiler. The contractors are saying they will bring in a sectional cast iron unit. These are the ones that scare me. I have heard to not expect more than 20 years at best.

Boilerpro_3

Say, Gene from you Address

it looks like you are in Chicago! I'm about two hours west of downtown. You may want to look at several smaller steam boiler step fired to meet your load. Slant fin has thier Caravan step fired steam boilers. Noel of Slantfin should be around here somewhere to help you out. With steam systems being so oversized, you could see some huge fuel savings by going to modular steam. You would probably heat the structure with only a quarter the capacity most of the winter if you have zoning or TRV's. Just finished pulling out a Kewanee steamer out here in a big church (churches are my speciality in the commerical realm)and are converting the heating system to all hot water (was a mixed system), but leaving the make up air in steam (budget limitations). On a previous steam conversion, we pulled out a 1 mil btu 12 year old WM sectional and put in two 240,000 Dunkirk package units and dropped fuel usage about 60%. Typically I see about 40%to 50% when switching to modulars with good controls in church applications.

Boilerpro

chris smith

cast and steam

i currently service a circa 1965 smith 450mils, oil fired steam boiler about top out about 45 gallons an hour it has been a great boiler, years ago we fired it with 4 oil

chris smith

paradise porter maine

jeff cook

Cast iron boilers last a long time

I installed boilers exclusivly for ten years I changed out dozens of 1950's boilers that were still in exelent condition. They were being replaced because the house was going up for sale or there oil company was looking for wook and offered them a great deal. The warmer the return water the longer the boiler will last. I have even removed the chambers out off many of them and never had to replace them years later because they were burnt out. On the other hand I did it to a steam bioler and ywo years later it craced at the target wall location. Cast Iron in a low mass 82% is a great investment it will out last you the proof is in the pudding