vents on Mains

alanm

I have a house built in 1896 that originally used coal as the heat source . At some point, they switched it to oil. system never seemed to work well (short cycling, uneven heat, etc). There is , I believe a return vent (see photo) , at the heater but with all the mains running in the basement, there are no vents on them . Should they have them and if so, could this be causing the problems?

BobC

That is a Hoffman 75 vent and it might be to small, also it looks like you have 2 mains and there should be an air vent towards the end of each main to vent the air quickly. Tell us how long each steam main is and what size pipe so we can tell you how much venting you should have.

Another issue is the copper pipes coming off the boiler header are too small. They should be steel and they should be the full size of the steam mains (look to be 2").

Is this a single pipe steam system? If so what kind of vents are on the radiators?

Bob

alanm

Bob….not sure if still following…..was getting fed up with the system. when they replaced the boiler that had steel……they went back with copper….they said it was fine and i was too naive to question them further. it is a single pipe system… few questions:

1. on the one main, that is feeding jsut 3 radiators ….there is no return pipe so where would you put the valve? these 3 also seem to be the hardest to get to heat.
2. Besides the hoffman 75, what should i put in there?
3. having undersized and copper piping…what would i notice in the system

thanks

Alan

delcrossv

See your other thread here:

https://forum.heatinghelp.com/discussion/198233/vent-at-end-of-main

ethicalpaul

Hey Bob, not sure you're still following…9 years later 😅

Just teasing @alanm but where have you been? Welcome back!

alanm

thanks!….at times i just get fed up with the system for when i would have contractors over….seems each one tells a different story!….anyway…wanted to follow up ……i know bob said there should not be copper….unfortuantey, i wasnt paying attention and when they replaced the boiler that is what they went back with……having copper piping instead of steel….what problems/issues would i see with the system? i was going to insulate the copper ….but should i insulate the steel also? thanks

Jamie Hall

There are two potential problems with copper — and both relate to the fact that it expands more than iron or steel. One is that the stress on soldered joints may — I'd say will — eventually crack them and they will drip. The other is that the expanding copper may push on the boiler sections and cause leaks to develop between sections.

Now. Both of those problems can be overcome by good piping design which allows the copper to expand without stressing the iron and without putting a twist on joints — or for the twisting by using joints, such as ProPress, which can twist slightly without much stress.

So whether the copper will be a problem or not depends entirely on how the piping is arranged.

Regarding insulation — insulate everything which carries steam, to the extent you can.

alanm

thanks……i have not noticed any leaks from the copper…yet!…..would i notice any issues on how the system is working?