Best way to repipe header?

Gary_17

2 2" supplies off 3" header. 1st pic looking away from supply, 1st takeoff works great 2nd not so good. I think it has to do with the 2 closely spaced elbows so I think it needs repiped. My main concern is I get the 2nd one working then the 1st one is affected. I could switch them or just try to hook them up more direct. Could I could I eliminate the 45's and have them go straight up? The problem supply is slightly longer but has 1 less rad all the vents have been replaced and work. W-M Gold oil installed 8 yrs ago.

Fred

What size is the riser out of the boiler to the header? What size vents do you have on the Mains? How many vents per main? what are the lengths of each Main?

KC_Jones

Fred asks the right questions. I have a feeling you are looking in the wrong place. If a main isn't heating well generally it's a venting issue. That piping is unusual, but I can't really see it causing a heating issue. 3" header is good and it appears to be a 3" riser as well. What size boiler is this?

EBEBRATT-Ed

I agree look at the venting. Changing the piping probably won't help. It's not "classic" piping but the installer was a little creative. I like creative. Unless there is something wrong with the piping that is not shown in the picture it should work ok.

Gary_17

3 section boiler. 3" riser 2" main 1@40' the other 45' w/a #75 at each end. I removed the one on the problem main and it still took awhile for the steam to reach it . Worked fine until the boiler and near boiler piping were replaced. When it's real cold w/Long runs it works. That's why I'm looking at the piping

Fred

You need the equalivent of two Gorton #2 vents on each main to get bthe air out of those mains in a reasonable time. It takes about 3 to 4 Hoffman #75's to equal a Gorton #2 so you are way under ventedd. Focus on the vents. The boiler piping isn't going to fix the issue you have.

Gary_17

OK but why is the 1 venting way better than the other 1? The shorter run (which works) has 5 rads and 4 90s and the longer 1 has 4rads and just 2 90s. It's a simple perimeter design w/1st and 2nd floor rads from each main.

BobC

Old houses settle, you might have a sag in the slow main. Stretch a string along that main and eyeball it in relation to the main to see of there are sags in the piping. Also make sure the main has decent slope so water finds it's way back to the boiler.

Bob

Fred

Steam is going to take the path of least resistance. While the shorter Main has 4 elbows, it is shorter, has more rads (with venting) and has a main vent equal to the longer main which has more air to expell.

Gary_17

It's only about 5-7 ft longer and the rad vents were adjusted to vent slower. The good side was completely hot and the burner went off on pressure and only the 1st rad on the other side was getting hot

Fred

Gary said:

It's only about 5-7 ft longer and the rad vents were adjusted to vent slower. The good side was completely hot and the burner went off on pressure and only the 1st rad on the other side was getting hot

After all is said and done, the header is OK and the issue is Main venting. Instead of spending money reconfiguring the header, buy 2 Gorton #2's for each main and put them on at the end of the Mains. Your problem will be fixed. Also, make sure the Pressuretrol is set for a Cut-out Pressure (Main scale) of 1.5PSI and a Differential (Differential scale) of 1, if you have a subtractive Pressuretrol OR
If you have an Additive Pressuretrol (Gray colored unit) The front scale is set at at .5PSI and inside the front cover of the box there is a white wheel, set it to "1" facing the front of the unit.
Edited to correct pressure setting.

KC_Jones

How long does it take to vent your mains currently? With mains that long I would guess with proper venting and insulation you should be able to fill them both completely in about 3-4 minutes. Do you know how long it takes currently from the time the header is hot to the time the end of the main is hot?

stanzygo

venting, some insulation would help. looks like there isnt any? maybe im blind. pressuretrol settings would affect it like the rest said. just my two cents hehe