Fast Venting

nicholas bonham-carter

check the pitch of the pipes along their length for sags which could trap the air, and steam. get a non-contact thermometer and after measuring the "time to boil" temperature on the steam header, then find out how soon steam arrives at the dry return. it the boiler is steaming up quickly, then steam is somehow being interupted on its way to the end. if the boiler is slow to steam, is it undersized [or worse]?--nbc

George_47

Fast Venting

I recently fast vented my mains.
Main feed 61 feet of 2 1/2" pipe with 2 Gorton # 2's at 16 inches from the end.
Secondary feed 51 feet of 2" pipe with 1 Gorton # 2 at the end.

Before the venting was completed the steam would take 14 minutes from boiler turn on to steam at the end of the mains.

Since venting the mains, I have had no improvement in the mains venting! Still takes 14 to 16 minutes for the mains to vent the air.

I checked that each Gorton valve was working. Also checked to see if the venting was quicker without any vents at all - just left the tapped hole. Still no improvement.

So it would seem to be a boiler issue. Any ideas what to check next.

George_47

The boiler reaches boiling point in under three minutes. The steam is just travelling slowly along the main feeds. There appear to be no obvious sags, but I will be checking with a level to be sure.

I have discovered a riser to no-where. It is in the middle of the main feed. The riser has obviously been capped off on the second floor behind the wall. Would this perhaps create an air block?

I also have a damaged radiator on the third floor which is turned off. Could this also be contributing to lack steam flow?

Thank you for all the inputs.

G Waite

Are the pipes insulated? Could the steam be returning to solid state?

George_47

No, the pipes are not insulated. I was trying to optimize venting first and any problems there might be with pipe pitch, sags etc before insulating. Have only owned the house a month so I am trying to figure the system out first before covering with insulation.

G Waite

I would love to hear another opinion but you need the pipes to be insulated or you are just wasting energy. If the pipes are cold it will take a long time for the steam to get there.

gerry gill

what vents

were on the mains before?

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Jamie Hall

Sounds to me, too

like this one is insulation -- the steam has to heat the pipes before it can travel farther. Insulaton on steam mains is not there just to prevent heat loss!

Steamhead (in transit)

I think

there's more to it than that. The boiler may be dirty, under-fired, etc.

George, have you tried the Find a Professional page of this site? You'll find it on the menu under Resources at the top of this page.

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gerry gill

i Know, me thinks so too.

my first thought was does the boiler have a hole in it?

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scrook_3

insulation, etc.

Even properly insulated, the mains have to be heated -- though they're losing a lot less heat from the outside so will heat a bit faster, and will load the boiler less, something else sounds amiss.

What brand/model boiler, what fuel, how many rads, and what type & how big, i.e. what's the connected load?