Vent-rite #1 adjustable vents

PinkTavo

Took Steamhead's recommendation (from a post a while back) and bought 5 Vent-rite #1 adjustable vents to replace old vents that were about 10 years old and not performing/worn out. We had the Hoffman 1A adjustables, which worked OK, but are not as easy for the family to fine tune.

Now it is just a dial with numbers on it. We got them dialed in this week. The only one we will tweek is the master bedroom, as there are some hot-flashes going on in the house! Bought them at Supplyhouse.com, very good price, quick shipping.

Next up (this summer just in case I run into issues) is a Big-Mouth main vent, and adding a vent to the 2nd smaller branch, that has a plug in the right location, but has never had a vent.

Abracadabra

You should vent the mains properly first then deal with the radiators. You'll probably have to readjust the radiator vents after adding the new main venting.

MilanD

I agree with Abracadabra. Without proper main venting you are additionally wasting fuel fighting the back pressure from slow air venting.

PinkTavo

Abracadbra and MilanD....I realized that my Main may be bad. Posted another post. Current is a Hoffman 4A. Small EDR = 210 sf. Do you think a direct replacement will provide enough venting? I want to do a Big Mouth, but clearance is an issue. Thanks.

MilanD

@PinkTavo

Big mouth is, I believe 4-1/4 when tailpiece is 1/2 inch in the fitting. @Sailah can confirm, or look through first few pages on this thread.

http://forum.heatinghelp.com/discussion/comment/1461097#Comment_1461097

Barnes and Jones also sells a vari vent main vent. @Sailah can let you know how to get it, if that's what you need to accommodate hight restrictions. It's currently out on Amazon.

https://smile.amazon.com/gp/aw/d/B01GQP0DQ8/ref=aw_pd_cart_vw_1_1?ie=UTF8&psc=1&refRID=8PX95A9KZTCE7NP0HNBS

Remember that you want both your mains to vent evenly. If the lenghts and pipe sizes are drastically different, longer main needs more venting and shorter probably less so the steam would arrive at the end of each main at the same time. So, this is trial and error, or you can use this online tool, calcate volume of each run and decide which vent to use accordingly. A big mouth on both ends, if main size diameter is the same, will vent shorter main quicker. So longer main may need 2 big mouths, or a big mouth and a gorton 2, or hoffman 75... Or, shorter may do with a main vari vent or a hoffman 75, while longer one keeps 1 big mouth.

http://www.rhomarwater.com/calculators/pipe-volume-calculator

At any rate, you want the boiler not to fight the back pressure from the air still in the mains, so depending on boiler sizing vs. edr, one of each may be enough as long as pressure stays at 0-6oz for most of the heating cycle.

Most widely used Honeywell pressuretrol has a minimal cut out at 1.5 psi, so the system should, ideally, stay close to the 0-6oz for the majority of the cycle and build the pressure to 1.5 psi at the very end, when all mains and rads are at full capacity. Some early 0-6 oz pressure will build depending on the main and rad risers lengths to overcome the friction. That too can be looked up to dial all this in.

PinkTavo

Thanks for all the info....am going to add the Big Mouth in place of the existing for now and then a Barnes and Jones Vari-Vent on the small branch this summer.

MilanD

Scrape off any paint around the threads of any plug you are to remove for this vent, and use a drop or 5 of Kroil or PB Blaster - just don't go overboard with it. I like Kroil as it smells much nicer. Watch it go down the threads, tap on the fitting and then wait 10 min or so to let it work itself down the thread. Use as big a wrench you can, or a breaker bar on a smaller pipe wrench, and give it gentle yanks to break it loose. Gently gently so the fitting or the plug don't cack or break. I sometimes try to give it a yank while tightening the plug first, then go the other way. Lever is the key. The bigger the better.

Best of luck!

PinkTavo

MilanD, thanks for the advice.