Convert steam cast iron radiator to water

John Evangelista

Can someone detail for me or point me in the right direction so I can convert my old steam radiator to a hot water radiator. I have read a lot of articles but they are not in detail. I have single pipe Steam radiators. There is a steam feed the main and then the valve on the top of the opposite end. I'm not sure how to connect up the hot water feed into the radiator and where the return goes. A picture diagram would be great but have been unable to find one. I hope someone can help. Thanks in advance.

Steamhead (in transit)

You may not be able to convert them

post some pics here and we can tell you more.

Why do you want to convert from steam to hot water in the first place? Doing so can invite trouble- go here for more:

http://www.heatinghelp.com/newsletter.cfm?Id=22

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David Efflandt_2

The sections of 1-pipe radiators are only connected at the bottom. Steam comes in one end, fills each section from the top down from that end driving the air to the next section as it heats each section towards the air vent. That type of radiator is not suitable for hot water because you would need to be able to vent air from the top of "each" section, and not very efficient since hot water would not flow to the top except by convection within the narrow confines of each section.

2-pipe radiators sections are connected top and bottom, and if used on 1-pipe steam, heat across and down (instead of one section at a time). Those would likely have large pipe taps at top and bottom of each end (which on 1-pipe steam would be plugged except one at the bottom). Those may be suitable for hot water (if they can take the pressure without leaking), but would have less heat output than steam.

So if your boiler only runs for a short period of time in mild weather and only heats some of the sections, the radiators may not be suitable for hot water.

Something else to think about. My gas bill for 1-pipe steam the entire 05/06 heating season (minus typical monthly summer gas water heater) in Chicago area was less than $470 (mild winter). Lets say it would normally be about $800. If I had a totally new hot water system that improved efficiency from 80% to 95% I would save maybe $150/yr. How many years would it take to recover the cost of a new system at that rate vs. investing that money (unless existing boiler is broken beyond repair)? I have no desire to part with my simple comfortable 1-pipe steam (not a mystery when you understand it).

Christian Egli_2

Kiss kiss

David is right on the money. Steam heat does not mean expensive. What it does mean is heart melting comfort in front of the cozy radiator alive with steam. Why douse this comfort with a flood of water?

To add a bit more depth to the newly found $150 annual savings.

Of these savings, the homeowners does not get to keep the huge chunk of change eaten in electric costs to drive the water circulator and to drive the condensing flue gas fan. These may seem insignificant but they are not. Definitely not. Unless you are also willing to say a possible $150 savings is mere pennies.

Things that last forever are free.

We are just in the beginning years of condensing boilers. What has already become apparent in Europe is that these gadgets are short lived. Once the engine light comes on, it is usually cheaper to buy and install a new machine altogether.

Notice how I said cheaper when talking about the cost of a new boiler installation? As if this too was but mere pennies.

This may all very well make sense, but I don't think the $150 begins to cover this rapid amortization cost. And again, compare all this to a steam boiler that has no complex moving parts to shorten its long life expectancy, and you have a case of the tortoise and the hare. If your tortoise has a limp, either fix it or shoot a hole in the paws of the hare in order to make the race fair.

Steam systems reward you with big savings for maintaining them properly.

There is more. Do you think steam is a low achieving antiquity?

Steam is a heating medium that comes with a brain. It figures out all on its own where to go heat the coldest part in your system. It is even so smart it has grown itself some feet, like us. Steam moves all on its own for no extra cost.

This sheer wit can only be matched in an ultra modern condensing hot water boiler by using smart pumps (which you pay for) and loads of smart electronic control (which you pay for).

As far as our boiler manufacturing companies are concerned, how do you make money selling things that come free? In comparison, selling boilers like hot cakes has just got to be more appealing.

If you have steam in the first place, you should consider yourself the luckiest person on the block. Lucky you, David.

Keep warm.