Old basic gravity hot water boiler

Sanddy0908

Can a convert an old gravity hot water boiler into a steam system leaving old piping to radiator in place?

Jamie Hall

Very unlikely. Nothing's impossible, but... why not convert to a pumped circulation hot water system?

The Steam Whisperer

I would say very likely, but you need to hire someone that knows steam to check it out and do it.

pecmsg

Sanddy0908 said:

Can a convert an old gravity hot water boiler into a steam system leaving old piping to radiator in place?

Highly doubtful. Different dynamics steam / water

Sanddy0908

I understand, besides of the system not having a steam trap, doe sit nees to have a pipe in the high side or it can do it with a low piped

Gilmorrie

Why are you wanting to do that?

JUGHNE

Can you post pictures of the boiler showing the piping around it, floor to ceiling?

Sanddy0908

The issue i have is that i am an idiot, i went to see the job and just look fast at the basement and been an idiot went ahead and thought the system was steam and order and installed an steam boiler. I found out when i saw how the radiator were vented and the steam boiler was going of on 5 psi of pressure.Technically no vents for a steam system. I order to main air vents for the two returns. I installed them and got rid off the expansion tank in the attic. It seems to be working every radiator is getting hot. But would it keep workingbor would it just fill up with water with time? 

Sanddy0908

Ironman

  

Steamhead

What you want to do is change the boiler to work with hot-water, and change the piping appropriately.

Sanddy0908

mattmia2

Like @Steamhead said, change the boiler trim to hot ware and add a small circulator. I think you might want to find a contractor that knows hot water well to help you that can help you learn since you will have to do a few minor things to convert from the gravity system with an open expansion tank to a system with a circulator and modern expansion tank and air removal. None of it is difficult or particularly expensive but you will have to have a good knowledge of hot water to make it work well.

Sanddy0908

@mattmia2 you mean to change a setting in the steam boiler to set it to work as a hot water boiler? Please explain and sorry for my dumbness i would like to learn more

mattmia2

It is more than settings. You remove the site glass, add a combination aquastat of some sort, change the relief valve, add an expansion tank and prv and air elimination, add a circulator, change some piping, add a tridicator, plug some unused tapings. Most boilers can be set up for steam or how water but they use different controls and accessories for each application. The manual may have a diagram although many don't put the air elimination, expansion tank, and circulator in the best location.

Sanddy0908

@mattmia2 thanks so much for the advice will follow i appreciate the information thanks

The Steam Whisperer

Yes, to make the system work as steam you'd need to change at least some of the near boiler piping to add drip lines to the supplies since they drain back toward the boiler (typically), add orifices to the radiator supply valves to control the steam distribution and provide air venting on the return mains. May some main vents at the end of the mains might be needed to get the steam out to the end of the mains quickly.

The other alternative is to set up the boiler for hot water and repipe it and add all the necessary additional equipment for a hot water system....pressure reducing valve, hot water pressure relief valve, aquastat and circulator relay, circulator, air seperation equipment, isolation valve to service the boiler, and a compression tank or two depending on water volume of the system.

After all that, it may just be easier to complete the conversion to steam.

EBEBRATT-Ed

JUGHNE

When this heats, where is the water line in the sight glass?

Could the system be completely full of water and working by gravity?

Depending upon the height of the house, if it were completely full, water pressure would open the pressure switch.

What did the attic expansion tank do when first turned on?
Where is the overflow pipe directed to?

Sanddy0908

@JUGHNE, ghe water goes a bit low when it is operating, it does not go full pressure doesn't go up anymore after i added the main vents in the two main return lines, and i removed the expension tank and cap the pipe that was going to it.

KC_Jones

Did you ask the customer if they want their system converted to steam?

It’s their house I really don’t see how you think you have the right to make dramatic decisions about someone else’s house like this, it’s dishonest at the minimum.  Does the homeowner even know how badly you messed up?

How did you size the boiler?  Hot water requires a heatloss calculation, steam requires measuring all radiators.  You say you didn’t go through the house so I can’t see how you could have even sized it properly.

Since I’m assuming you didn’t ask prior to doing the work, all the cost of conversion should be on you at this point.  If you put it back to hot water, which, in my opinion is the only option, I can see them paying some as you should have quotes that in the first place.

If the customer agrees to steam, Next step is repiping all the radiators for steam traps, making sure all piping in the basement and at the radiators is sloped properly among other things.

So many questions.  What did you think when you tore out the expansion tank for hot water?  What did you think when draining the entire system of water?  I can’t imagine on any planet how all those clues came up and it never dawned on you this was a hot water system.

WMno57

This is why I DIY.

ChrisJ

WMno57 said:

This is why I DIY.

You and me both my friend.  You and me both.....

Sanddy0908

@KC_Jones yea i mess up big. I did measure the radiators and came up with the calculations for the sq footage of steam needed, where i mess up the most it was that it is my first time seem a gravity hot water system. I guess there is always a first time. Everything is slope as it should. I didnt see the expansion tank till the new boiler was in and the eye opening was when i was draining the system that when i noticed i have messed  up.

KC_Jones

Sanddy0908 said:

@KC_Jones yea i mess up big. I did measure the radiators and came up with the calculations for the sq footage of steam needed, where i mess up the most it was that it is my first time seem a gravity hot water system. I guess there is always a first time. Everything is slope as it should. I didnt see the expansion tank till the new boiler was in and the eye opening was when i was draining the system that when i noticed i have messed  up.

These questions still stand:

"Did you ask the customer if they want their system converted to steam?

It’s their house I really don’t see how you think you have the right to make dramatic decisions about someone else’s house like this, it’s dishonest at the minimum. Does the homeowner even know how badly you messed up?"

As a homeowner this whole situation has my blood boiling. I am knowledgeable and know better, but this homeowner I'm guessing does not. The OP appears to be trying to pull the wool over their eyes and get away with something instead of being honest about it. You made a mistake, fess up to it and make it right, and making it right could mean a whole new properly sized and installed hydronic (not steam) boiler. The way you sized it is wrong for water, the way you piped it is wrong, the way you apparently quoted it is wrong.

This is a hot water system, you should not be attempting a conversion unless you have explicit written permission from the homeowner to do such and the homeowner is clear on the implications of such a conversion, which I question if you even know. As said above this is dishonest at a minimum.

We all make mistakes, it's what we do after that makes all the difference.

JUGHNE

The homeowner may be afraid of having steam.
Hot water gravity was developed over 100 years ago as an alternative to steam heat which has a bad reputation of explosions.
Gravity was used because there were no pumps for hot water and in some cases no electricity.

All history, but the word of "steam" has been ingrained in some people's mind as dangerous.

You should check with the boiler manf. if this steamer could be converted to hot water. Often it is the same boiler with different trim.

You could get all the hot water trim that would have come with HW boiler.
Every safety device must be installed.

If you used both supply and returns provided and piped them to the full size, you might get the gravity flow restored without a pump.
The existing attic exp tank might be salvageable if you haven't burned that bridge completely.

The HO had the simplest system possible. The only moving part was the gas valve.

Steam will give them more devices that will need attention. LWCO probe, sight glass, water feeder perhaps, more flushing needed, skimming off oils, etc.

Where are you located? Is your work subject to local inspections?