Jump to content

Boiler Questions ???

member deleted

Recommended Posts

I inspected a 86 year old house today for the sellers. They were not present and the gas and water were shut off. Actually, the gas meter was missing from the side of the house.

Anyway, my inspection of the boiler was limited since the gas was shut off. The boiler is a forced hot water hydronic system. But the expansion tank was located in the attic on the other side of the house. The house had old cast iron radiators.

Could an old gravity hot water system be converted to a forced hot water system and still utilize the old expansion tank? It would seem to me that the closed system would have to have a sealed expansion tank rather than a tank that is open to the atmosphere.

Any advice?


Download Attachment: icon_photo.gif jpg4.jpg

269.89 KB

Download Attachment: icon_photo.gif jpg5.jpg

219.78 KB

Link to comment
Share on other sites

Judging from the plumbing @ the expansion tank the original system was open to atmosphere and had no pressure on it. The tank was just a buffer zone to accomodate the thermal expansion / contraction of the water as the boiler cycled..or was fed coal.

The "new" boiler looks 15 years old at least and the tank has been working and may still be open to atmosphere...which is OK, I guess. I'd want a manual re-set low water shut off installed. The PRV in the picture though would have no real function if the system is open to atmosphere so I'd surmise that it's a closed system at this point. If that's the case, I'd replace the old copper tank w/ a steel, bladder type expansion tank. You just don't know what pressure is going to blow that old tank up.

The whole install is kinda ugly.

Link to comment
Share on other sites

Are you sure there isn't a modern type expansion tank near the boiler? If there is indeed an open tank (hooked up), I'd go for the modern tank. For a number of reasons.

Prevents air entrainment into system, easier to service, smarter, not dumb, cheap to install, etc. Nutty if there is an open tank. No 'holes' allowed in hydronic heat....cavitation.... cavitation... impeller damage... air-binding...

Link to comment
Share on other sites

You wouldn’t install an open expansion tank on a modern boiler installation. If in fact it is still in use it should have been changed out to a closed tank (bladder style) or at least that’s what a quality mechanical contractor would do. I would imagine that it could still function though. Did you happen to note what the idle pressure was on the boiler? Did it have a PRV on the city water line? Old radiators that were meant for steam will also work with hot water system however; they take a long time to heat up and may not provide the comfy heat the new home owner might expect.

What’s up with the peg board in front of the boiler? Is half of the boiler in some make-shift work bench?? I can't imagine what that bumpout is. Whatever that is though it does have a lovely coat of white paint!

Another thing I can’t see too well, does the hot water tank & boiler have a TPR? It would appear from the photo that the gas fired hot water tank seems to be sitting on a wooden platform too, that’s nice. It also has some scorch marks around the inspection plate, draft any good? Is there some kind of pipe chase below the hot water tank?

I’m sorry, what was the question again?

Link to comment
Share on other sites

  • 2 months later...

if you look at the picture and you should see what is their ive worked on this type of boiler and others for 18yrs and yes their is a tpr and what are you worried about having it done manualy thats how its done, every thing works together the gray box is for adjusting the temp as well inside the temp when it shuts off, the bladder is in the attic, ive heard of this before my preferance is next to the boiler and you only need 12 pds of pressure on the reading and the pump must work you can have it run all the time or cyle on and off looks old? but it should work as long as its not leaking just clean it out inside it should have 5 arms make sure that the are clear and the flue is in good shape i could go on but like he said no water no check and the gauges would tell it all, the air graber should be replaced its bent

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...