Getting my 1924 system going again

Budward

Hi all, new guy here with first post.

My house, built in 1924, has the original boiler and radiators. Bought it in 1987 and enjoyed our first experience with radiators. After installing central heat and AC in 1995, we continued to use the radiators as the main heat source until 2003. After that, we used it "some" every winter, for a while. It probably hasn't been used at all now since maybe 2015-ish.

Some facts. It appears that the boiler was converted from coal to gas shortly after the house was built. It's controlled by a Minneapolis Honeywell gas valve and 3-wire thermostat, both appearing to my (limited) knowledge to be series 10 of 1920s vintage. House is 1800 sq ft, only one BR and bath on 2nd floor. 7 radiators downstairs, 2 up. Gravity circulation. Best of my knowledge, the piping has never been touched, except for (1) when we removed, then reinstalled the 2 bathroom radiators during a remodel 20 years ago and (2) previous owner swapped

out big upstairs bedroom radiator for a smaller one, long before we bought the house. The boiler and expansion tank are in the basement.

I want to get it checked out and back into use. Apart from liking the uniform heat, the gas valve can be turned on manually, giving us heat when there's an extended power outage. That was a game changer during the one-week outage from an epic ice storm in 1994.

The last time I started the boiler, it only made a little heat for the radiators closest to it and the pressure gauge on top never came up to normal.

So, your suggestions? Or can you point me to some useful links?

Our new HVAC company say they service radiator heat, so I might let them take a look, although you never know how that might go…

Best to all,

Buddy

SlamDunk

Very doable and worthwhile!

Budward

https://forum.heatinghelp.com/discussion/comment/1811265#Comment_1811265

I'm sure you're right. I just need some guidance. I'm quite mechanical, but I've got zero experience with radiator heat, other than an annual bleed back when we were using it. FWIW, I just bought Classic Hydronics by Dan Holohan to start getting better informed.

delcrossv

Drain compression tank?

Bleed radiators?

Boiler clean?

Burner working correctly?

That's pretty much it for a gravity system.

+1 on getting Classic Hydronics.

leonz

Purchase the books CLASSIC HYDRONICS and "HOW COME?", From the Heating Help bookstore and read them and read them again before you go anywhere near that boiler with a wrench.

Is there an open to air expansion tank in the attic or are the radiators used to act as the compression tank??

delcrossv

https://forum.heatinghelp.com/discussion/comment/1811272#Comment_1811272

There's a tank in the basement. Shows in his pics.

Steamhead

@Budward , where are you located? We might know someone who can help you with this.

EdTheHeaterMan

You should be able to do this yourself if you have any mechanical ability.

However if you are like my brother-in-law then you should call a Pro.

You need to locate three valves. One on the expansion tank out of site on the photo.. another is the one that adds cold water to the system. The final is the drain valve near the bottom of the boiler. If you can locate them, We can help you. But you should still get the two books mentioned above, That is @DanHolohan retirement fund, since @Erin Holohan Haskell college fund is finished. (inside joke)

Some pictyures from farther back and at different points of view will help.

mattmia2

You should find someone that understands that type of burner and make sure it is burning properly. In that type of installation the boiler and vent connector and chimney are all one system that affect how the burner burns. You can clock the meter to diagnose your current problem, I suspect either the regulator or the valve have gone bad and it is underfiring but ultimately you need someone good with combustion to look at it.

Also make sure the boiler is full of water.

EdTheHeaterMan

@Budward. Looking at your gauge, you probably have to fill and vent the radiators. I'm guessing that your burner worked or is working by the normal thermostat and pilot lighting instructions. If the flame is not happening, then go with @mattmia2's suggestion.

As far as getting the water side right Follow these instructions:

To start with, you need an empty expansion tank. To accomplish that we are going to use valve #1 to let air in the tank while water is draining out the bottom of the boiler #3. First thing is to connect a garden hose to the boiler drain valve #3 and put the other end near the floor drain. If you don't have a floor drain, then you will need use a pump or buckets to get the water out of the basement.

After opening the boiler drain, look at the gauge to see the pressure drop to zero. Once you get that done, you can open valve #1 to let air in the tank. You will hear the gurgling at valve #1. Once the tank is empty, You will hear air bubbles gurgle near the pipe that connects the tank to the boiler supply pipe. Now you know the tank is empty. Shut off valve #1 and #3.

Once that is done, you now can open valve #3 to put water pressure back in the boiler. You will watch the gauge while your helper lets the air out of the radiators until they get a small spirt of water in a can, then they will close the radiator vent and move on to the next. You will continue to add water to the boiler making sure the gauge does no go over 18 PSI. But must always have at least 12 PSI on the gauge. Your job is to open and close valve #2 as needed to maintain that pressure.

Any Questions?

Big Ed_4

I would recommend up grading the gas burner and check the chamber , The boiler part ( pot on the stove ) would last another 100 years ….

The series 10 , Replace thermostat and aquastat ……

EdTheHeaterMan

Series 10 controls are no longer available new. You may find some available as new old stock on ebay or Craig's List. But that is not necessary, the series 80 controls are interchangeable with series 10 by just eliminating the R terminal and connecting the series 80 terminal marked R to the series 10 terminal marked B. If the calibration is within acceptable limits, then just leave them alone until they don't work.

Budward

https://forum.heatinghelp.com/discussion/comment/1811278#Comment_1811278

Memphis

Budward

Thanks to all for thoughtful replies. Just so you know, I've got travel coming soon, so this process will likely drag out over several weeks. Job one will be finishing rehab of the thermostat, confirming low voltage feed to it, reinstalling it, confirming 110 VAC to the relay at the boiler, confirming that the pilot is still lit, and then testing to see if the boiler will fire up when the thermostat is adjusted (shutting off immediately if it does).

Any thoughts about that process?

The vintage Minneapolis Honeywell thermostat worked perfectly when I last used the system. A previous owner of the house had slopped paint all over it, so I removed it,

dismantled it, and stripped the paint. Not to worry, I've marked how to correctly reconnect it and I haven't disturbed the "clock spring" or the two tiny adjustable screws that time the Off and On of the thin and thick ears. I also bought two used thermostats off eBay for parts and as an undisturbed reference.

Here's the spare themostat. Mine is exactly the same, except for a fresh coat of bronze paint and my thermometer still works.

Budward

The drain and fill valves are both on the return on the right side of the boiler, as you face it. Also on the fill line, between the boiler inlet valve and the hot water heater are two red valves that look relatively recent. I take them to be a pressure relief valve and and one-way valve. Guessing these are both to insure isolation of the boiler return from the water heater, in the event of leakage from the boiler fill valve, which I'd assume would normally be closed?

Budward

I'm a little puzzled by the valves on the compression tank. There are two on the bottom that seem to me to do the same thing - drain it. Maybe it's just pipe thread vs. hose bib? I expected to find an air bleed on top of it, but no luck so far.

Budward

And finally, here's a closeup of the pressure gauge. If I understand it correctly, the big numbers are "differential pressure" added by heat and little numbers around the outside are gauge pressure to atmospheric. So the red "needle" on the gauge face seems to want 10psi gauge minimum in the system cold. @EdTheHeaterMan I'm getting ahead of myself, but I guess you set this in the drain-refill-bleed process that you outlined.

Looks like right now there is roughly 7.4 psi in the system. Assuming the gauge is still working correctly, at least it isn't zero, which is what I'd expect if there was a leak somewhere in the boiler, piping, and radiators. Is that right?

Budward

https://forum.heatinghelp.com/discussion/comment/1811282#Comment_1811282

@mattmia2 I haven't disturbed any of the boiler controls, vents, etc. since it was working well when I last used it. Once I get through the thermostat rehab and test fire it, how would I know if there is a problem with the regulator or valve? Or do I just proceed with @EdTheHeaterMan instructions to drain-refill-bleed and then - if it makes good heat at the radiators - call it good.

PC7060

https://forum.heatinghelp.com/discussion/comment/1811316#Comment_1811316

I’m not surprised there isn’t an air bleed on tank. You may find a plug but my tank didn’t have have one. To drain it was simple process of closing valve between boiler and tank; attach hose and then drain. Be prepared for it to take a while since it will be sucking air to make up for vacuum created as water drains out.
Once you get it drain, you can open the valve leading to MPT connection to let air in. Just open it a bit so hopefully only air goes in and no water comes out.

EdTheHeaterMan

That setup on the tank is to make draining the tank a little easier. You do not need to do my first step from my previous post to drain the expansion tank. Someone else has made it easier. To start with an empty tank all you need to do is place the end of that hose in the floor drain or laundry tub.

1. Make sure valve #2 is closed
2. Open valve #4 and let the water out. Once the water has stopped flowing the pressure gauge on the boiler will be at or close to zero PSI
3. Open valve #1 and let air into the tank. You will hear air gurgling into the tank.
4. After some time the air starts to gurgle into the system, that means the tank is empty and you close all the valves.
5. Now open valve #2 to to add water to fill the system back to the proper pressure.

The two red valves are a relief valve and a pressure reducing valve the pressure reducing valve is also known as the automatic fill valve. It takes the house pressure of 30 to 70 PSI and reduces it to about 12 PSI. if it is working properly some folks leave the manual feed valve open so there is always 12 PSI pressure on the system. That way, if you are not getting any heat from any given radiator, you can just open the radiator vent and let air out. VIOLA »»» HEAT!

Jamie Hall

On the gauge — the red hand indicates maximum pressure reached. The black hand indicates the actual pressure in the boiler.

When you fill the boiler, you want the black hand to come alive (it may be) and let it come up to about 2 marks above the 10 mark (about 12 psi). That should be ample.

And on the thermostat —those aren't the most sophisticated, not do they hold that close a temperature — but they will last forever. Keep it.

Budward

https://forum.heatinghelp.com/discussion/comment/1811326#Comment_1811326

Respectfully, no. The red hand doesn't move - it's painted on the gauge face. I'm guessing they want it to call attention to the 10 psi minimum.

Otherwise, thanks. All stuff I'll do when I get to that point.

EdTheHeaterMan

That gauge was designed for the new coal boiler owner. An easy to read red line as the minimum pressure to be sure the boiler is filled with water. A zero to 30 PSI pressure gauge with increments that also start at 10 PSI (long before the 12 PSI standard was in place for closed systems) and end at 20 where 30 PSI actually is located. Also there are notes about cement at the base, and another note to read the instructions!!! Obviously the inability of the average male to read the instructions is a time honored tradition, that dates back at least one and a half centuries! LOL