Boiler Gate Valves

ScottMcNab

Hi
I have a conventional propane boiler with two supply pipes leaving the boiler and branching off into the house and returning as three and then into one big pipe back to the boiler. As they return and come into three, their are manual gate valves for each loop. Would I leave them open all the way or close them for more or less heat? I’m just confused as to why they’re on the return side and how to best manage the heat. The bedrooms upstairs are ridiculously hot and would like to spare some of that heat and use for the rest of the house. 
Thanks

Jamie Hall

All these pipes are connected to the steam side of the boiler either directly or through other pipes? No traps? So there is steam in all of them? And the three pipes join together before they drop to the boiler? And do they then go into a Hartford loop?

I think we need some pictures of this arrangement, from far enough so that we can really see what these pipes are doing and how high they are and how they connect to the boiler to make sense of this.

In any case, I think it is unlikely that manipulating those valves is going to help much. Keep in mind that a gate valve is either open or closed -- it cannot be left in an intermediate position.

JUGHNE

Can you post pictures of your boiler, include piping and the valves?
Also your heat emitters showing each end.

EBEBRATT-Ed

Is this hot water or steam?

@Youngplumber
Throtteling a gate valve is a no no. Ball valve or globe valves can be throttled

ScottMcNab

It’s hot water. I’ll add photos and then can answer questions you guys have. Thanks for the help. 

ScottMcNab

ScottMcNab

No arrows. They take five full turns to open from closed and the stem does move up and down. Just curious if open or closed would control heat in the three different heating areas. One controls upstairs, one controls bedroom and dining room and one controls living room, kitchen and bathroom. 

hot_rod

you can also close the dampers on the baseboards to get some adjustment, close down the overheating rooms. That would be a better option to throttling a gate valve.

ScottMcNab

Would opening or closing them a bit either way help keep the water warmer to the rest of the rads as to keep the boiler from not firing as often? Just seems like the water get cool quickly and the going through a lot of propane. Boiler fires for 15 minutes and off for 20-25 on a colder day and fires again. Does that seem normal?

pecmsg

Whats the water temperature set for 180° ? Lower it. Be careful not to go below 140°F.

ScottMcNab

It’s a cold start Biasi boiler. Thermostat controls the burner. Thermostat calls for heat, burner fires and circulator starts at 155 with a differential of 30 to protect against condensation as suggested by Biasi themselves. So circulator turns off at 125. And the cycle continues when a call for heat. 

pecmsg

Thats the circulator, whats the water temperature?

JUGHNE

Partially closed gate valves will rattle the "gate" and might eventually put enough wear on the parts to where you can not open nor close completely.

As Hot Rod said close the top dampers in the hot room.
If that does not do it then wrap part of the fins in aluminum foil.
These heat by air convection. If you restrict the upward air flow thru the element it cuts down on the heat output.

JUGHNE

So, maybe choice between $4 of tinfoil and $xxxx. of piping and valve change out.

Who knows, maybe the original print mentioned the tinfoil solution?

pecmsg

TACO has circulators that modulate to return water temperature.

hot_rod

Youngplumber said:

I'll just go on the record. I do not like the idea of covering up elements. Closing dampers on one thing, but the problem is within the piping or the length of element itself. As a construction pro for many years, tinfoil is rarely, in my opinion, a good option. Would you build something planning for tinfoil? Then why recommend using it?

Balancing valves are a real fix. Yes it cost more to do something right. 

Good day... 

When heat emitters are inn series like baseboard, the only easy way to change output is to slow the convection. If the dampers do not or will not adjust, not harm in using foil.
I've know heating guys to snip off fins to balance an overheating section of fin tube, if the foil frightens you.

HomerJSmith

You can close a gate valve 90% before you make any appreciable change. There's a term for it which I can't remember. It's used in balancing valves. A globe valve would be a better choice for throttling, but a balancing valve is best. It evens the flow of water, distributing heat energy where needed.

ScottMcNab

Thanks for all the input. If the valves are installed on the return side where they currently are, does reducing the flow or opening it right up make less heat in a room? Like slowing down the flow leave more heat at the rads or speeding up to full flow give more heat or is the water moving too quick to be effective?

Alan Welch

You could probably split it into 3 zones and have better control of the heat.