Antique Cast Iron Boiler-- Need advice!

HomeownerKate

I was reading the previous entries about antique cast iron boilers and I figured this might be the place to turn.

I own a home that was built in 1893. I bought it in 2009, and the home inspector and my Dad (a retired HVAC guy) agreed that this beast would probably continue to serve for many more years. My Dad said it was the same boiler he grew up shoveling coal into as a kid (he was born in 1929, and sadly is no longer here to advise me.) For all I know it was installed in the house when it was built! It was converted to natural gas at some point. In a Minnesota January my fuel costs are about $120.

It is quiet and efficient, circulating heat to all my rooms via radiators that have never once needed bleeding. I think I recall my Dad saying that the gauge should never rise above 16, and for the longest time it didn't, but has been creeping up.

I haven't ever added water, but I'm feeling like I ought to. I'm not entirely sure what these gauges measure, or where to add water (maybe it does that automatically?)

I sure appreciate your help and assistance. (I'm not going to replace it, so please just advise me on how to work with it. Thanks.)

mattmia2

Is there a tank hanging from the ceiling in the basement somewhere or up in the attic or on the top floor?

20 psi doesn't seem abnormal to me, but this is out of my realm. Someone that really knows what they are doing should be servicing it once a year or so.

PC7060

Hi Kate, welcome and thank for posting pictures of you cool old boiler. Looks like you have a hot water hydronic system so assuming all of the radiators are heating properly there is no need to add any water.  It fact it best to leave the deoxygenated water alone.  Your operating temperature of 180° Is pretty typical and the system pressure of 20PSI is a bit high. 

Do you have a overhead pressure tank? If so you may just need to drain it down, a simple operation. 

Can you post a few pictures of the piping off the top of the boiler, the pump (if any) and the pressure tank?  You can see an example of the tank in the background of this picture of the thrush valve which captures the air and feeds it to the tank. 
You should have something similar on your system. 

EBEBRATT-Ed

Look at the gauge closely> That's an altitude gauge, it's calibrated in ft of water not psi. I think your water level is fine if the gauge is correct.

@HomeownerKate

Just curious if you have someone to service that boiler? Most of the younger generation would like to toss it at first glance. They really don't make them like they used to.

As water is heated it expands when cool it shrinks. You have an expansion tank somewhere that stores the heated water when it heats up. It could be located above and around the boiler or it could be in your attic which was common back in the day.

On the left side of your boiler next to the vertical white return pipe is a black pipe with a valve (gas shut off for burner) and a silver pipe. There is also a silver pipe on the right side. One of those is likely the water make up valve. The other one could go to the expansion tank. Might be able to tell with more pictures

PC7060

Good catch on the meter, @EBEBRATT-Ed.  

So the pressure is sufficient to push the water 20 up into piping or approx 9 PSI?

Jamie Hall

PC7060 said:

Good catch on the meter, @EBEBRATT-Ed.  

So the pressure is sufficient to push the water 20 up into piping or approx 9 PSI?

Exactly. So much simpler to read and understand....

HomeownerKate

Thank you for the responses. I will add some additional pictures when I get home, of what I think is the expansion tank and other views you've asked for. There is no attic- this is a story and a half-- but I think there is a tank in the corner which must be it.

"Just curious if you have someone to service that boiler? Most of the younger generation would like to toss it at first glance. They really don't make them like they used to." The answer to @EBEBRATT-Ed's question is No. I haven't had anyone look at it because it has been working - so don't fix it if it ain't broke, right? Actually, I'm not sure who to call. I'm pretty sure most of the younger HVAC guys/gals I've encountered don't know much more about it than I do. At least, the folks I have had down there on other plumbing related issues haven't been able to tell me a thing. I cannot really afford to pay a service call just to have the person tell me they don't know. (Many of the companies around here charge just to send the truck out.)

I'm also a little bit afraid that someone who services it will red tag it (which happened to a friend when the service technician was unable to relight the pilot in the conversion box. Although his was a little different set-up- ca. 1920s.) and then I'll be forced to replace it. It is so quiet and effective that I really have no reason to replace it. I raise an eyebrow when I read that a modern boiler has an expected life span of 15-20 years. This old soul has been down there for 100 years!

So the gauge is not indicating raising pressure, but rather rising water level? I have a nagging fear that it might explode. Someone please tell me that that fear is irrational.

Thanks again,
Kate

EBEBRATT-Ed

@HomeownerKate

Explosion is not likely. Most pressure gauges are calibrated in PSI...pounds/sq inch yours measures water pressure but the gauge reads the pressure in Feet of Water, Yours reads 20' so thats enough for a 2 story house

Some day you will need a contractor, boilers are no different than cars. They should be checked and serviced. Should get some one lined up

mattmia2

If you learn a little about it you should be able to ask questions over the phone that will tell you if they understand it or not.

If you tell us where you are we may know of someone in the area.

BTW that insulation plastered on the boiler itself and most of the pipe insulation appears to be asbestos so don't disturb it.

JUGHNE

This looks to be a gravity flow hot water system. I see no pump, is there one?

In a gravity system the hot water moves up the large pipe on the top of the boiler, flows thru large pipes and returns thru the 2 smaller side pipes connected down low on either side of the boiler.
As the water heats and becomes more buoyant it rises and as it cools after flowing thru the radiators is becomes more dense and returns by gravity.

Your expansion tank may be a tank or box, open top or vented to the air.
It would be located above the highest radiator on the second floor.

A pipe is connected to the bottom from the "hot" side of the piping.
The water rises and falls as it is heated and cools.
Sometimes there is an overflow pipe that indicates the tank is full.
This overflow may be piped outside onto the roof or come down to the basement and be connected to the sewer drain pipes, you may not see any water come out anywhere if this is the case.

Dad may have been fooled by the height versus PSI reading as several here have, other then ED they are all young guys.
The adjustable red needle was probably set for maximum height of 30 feet.
30' is about 14 PSI of pressure.
Your 20' is about 11 PSI.

Show us more: where does the white pipe on the left connect and where does the white pipe on the right go to?
You can back up to show more of the boiler, floor to ceiling and that would make those obvious.

Is there a power switch anywhere or a device fastened to the ceiling on an electrical box. A picture of the thermostat would perhaps tell a lot.