Unequal heat & pressuretrol question

John Despres

First, this is a great site! Thanks to Dan and all you who post here. It's been a help so far!

Steam heat, one pipe system.

Ok, upstairs gets hotter than the dickens but downstairs sits in the low 60's. Upstairs, my son's room has hit 91 degrees. It's OK but the sand from the beach we installed is getting all over the house...

Here's what I've done so far based on what I learned here. Cleaned the vents on the mains. Checked the water quality (it's clean). Checked all the rad vents. Replaced those that need it. Dialed down the main pressure and dialed down the diff on the pressuretrol. Increased the water level a bit for better steam bubble expansion.

It worked!! The three rads that have never come on, heated up quite nicely. My wife called me Da Man! I blushed.

Alas, after two days, the system went back to it's old ways. It's cold down and hot up. All the rad vents were still clear and the vents on the mains were also clear.

I played with the pressuretrol (Honeywell type L404). I removed the cover and screwed the main and the diff all the way down to zero and crept them up to what looks like two pounds. (This is difficult as the marker increments are in fives on the main and ones on the diff.) How does one really know if the pressuretrol is working? How can I be certain it's set properly? Is there a way to set it by watching the mercury switch while adjusting the two levels? And what is the pressuretrol? Just exactly what does it do? And how does it work? And how do I know if I need to replace it?

I'm thinking of replacing the pressure guage with a more sensitive on as Dan recommends in the help portion of this site. (I've ordered Dan's book, too.) I think this will help with getting the pressure correct. Will it?

With exception of two rads out of 10, none have heated all the way across. Probably need the proper vents. I'm ordering Dan's radiator book to find out and get that much correct as I move through this.

Lastly, I enjoy learning and this site has been fun to explore!

Thanks much.

John

ta finnegan

Questions.

How is the water level, do you get surging, cutting off on low water at all?

Any hammering?

How are the returns? Below water line?

Venting on the main? Non-existent?

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John Despres

some answers

The water level seems fine. A bit less than halfway up the glass. No Surging. I've never let it get to low water level, so I don't know if it cuts off.

No hammering at all.

The returns are below the water line.

Both vents on the mains are open and venting.

Drod

Uneven heat

I've had great success with a similar problem, though not nearly as severe as yours, by changing my radiator vents to different sizes. You may need quicker venting ones on your cold rooms, and slower ones on your tropical rooms.