Boiler Temp - 100 degrees Fahrenheit

dbaron

I have a Burnham Series 2 (model "B") gas-fired boiler. When the temperature in our area gets below 25, the system cannot keep up. I do not believe it is air bound. The boiler appears to be firing fine and the circulator pumps sound and feel like they are whirring. But the pipes simply do not get warm enough to heat the house. I note that the temperature gauge on the boiler says the water temperature is 100 degrees Fahrenheit, which I believe is too low. There is a temperature gauge on the hot water storage unit that is set for 180 and one on the boiler itself (the high limit) that is set to 200. I can't understand why the boiler temperature is low and why the system does not adequately heat the house. The thermostats (two zones) are set to 67 and the interior temperature in both areas of the house is about 54. Thank you for any help and advice.

Ironman

How about some pics? That makes it much easier for us to see what you have.

Zman

The boiler is firing continuously but the pipes are not getting hot? Or is the boiler cycling. How old is the house? What type of radiators? How do the supply and return pipes feel?

unclejohn

Appears to be, or is firing fine. Is the flue pipe hot to the touch.

dbaron

Flue pipe is hot to the touch. Boiler fires fine and does not stop because temp is never reached - it is not cycling. All burners are on and the fire looks okay but in my non-expert opinion there looks to be a fair amount of yellow flame with the blue. The heating pipes are merely warm to the touch, but you can feel that all the (SlantFin) radiators are getting that minimal warmth. The return pipes are cooler. I'm not sure what I should take pics of but happy to take a pic of anything.

BobC

Have you clocked the gas meter to make sure the boiler is consuming the right amount of gas?

http://www.aprsupply.com/support/technical-support/checking-firing-rate-(clocking-meter)

If your consuming too little gas the boiler won't heat properly.

Bob

kcopp

Take some Pix of the boiler, the boiler piping and the radiators for starters.
How big is the house?
What is the insulation in the walls like?
How about the windows?
Sounds like to me the boiler is undersized or is has a huge load somewhere that is sucking the BTU out of it.

unclejohn

Is it possibly leaking and taking in fresh water? Do you have any buried pipe.

JUGHNE

Starting with simple questions.....Did it ever work good? When did this problem start? How many heating seasons have you lived there? Is the gas valve (shut off lever) that is outside of the boiler all the way open? Does your water heater (if a separate appliance) work OK?

icesailor

He mentioned something.

If it is warmer leaving the boiler than it is coming back, there's too much radiation and the heat loss is to great.

Or the boiler is way too small or the HX is dirty. Water side, fire side, or both.

John Mills_5

What size boiler? What size is the house? How many feet of baseboard?

dbaron

I will try to measure the volume of gas consumption. The difference between the supply and return side temp is not great but it is noticeable. The boiler is a Burnham Series 2 905 which is rated 107,000 BTU/hr and 82% efficiency. The house is 1600 square feet. It was gut renovated in the 1990s (when the boiler was put in) and the walls were insulated at that time. Also, the windows were replaced. We have lived in the house 5 years and I feel like the problem has gotten worse over the last 2 winters - essentially, whenever the outside temp drops below 25, the system is overwhelmed and cannot heat the house. I can measure the length of the slantfin radiators and get that information to you. I will also take pics.

I made sure the gas supply is all the way open. I have not measured gas pressure at the manifold. I would need to buy a gauge for that. The boiler has a third zone for the domestic hot water, and that seems to work fine. Though I did try shutting off the priority for the domestic hot water (that turned off the other circulator pumps when the hot water called to the boiler) and all it did was make the hot water cold - it did not seem to help move more heat to the other two zones.

unclejohn

If you have shut off or isolation valves at the boiler try shutting down the supply side valve and see if that raises the water temp leaving the boiler. Do you know what circulator you have on the system, some people call them pumps.

Snowmelt

How much baseboard do you have, linier feet of fines? Total piping including fines?

kcopp

Again pictures will help....

JUGHNE

How about a WAG for low gas pressure in cold weather when the demand of the neighborhood is high? service line to house or sluggish regulator. But still enough pressure to heat domestic water, taking longer than usual but eventually getting there.

Jean-David Beyer

Was it always like this, or did you change something from the time when it once worked?

Do you have outdoor reset? If so, perhaps something got adjusted wrongly.

If the highest temperature you can get out of the boiler is 100F, I wonder what the return water temperature of the water is.

You may need a pro in there to make sure the boiler is running correctly. Not just an ordinary plumber, but one who knows how to adjust a boiler. If he comes without a digital combustion analyzer, get someone else.

I have an 1150 square foot Cape Cod and I calculate 40,000 BTU/hour is enough to heat it down to 0F outdoors and 70F indoors. I happen to have an 80,000 BTU.hour (input) mod-con boiler with outdoor reset.

dbaron

Thanks to all for your questions and comments. Not sure what a WAG is. I have ordered a manometer to read the gas pressure at the manifold. I am attaching a few pictures of the boiler.

The circulators are Taco (Tako?) cylinders.

I measured 56 feet of slantfin baseboard radiator in the downstairs zone and 54 feet in the upstairs zone.

JUGHNE

A WAG is a "Wild Assumptive Guess" on my part that your gas delivery pressure may drop with colder outside temps. Perhaps due to more new gas customers in your neighborhood causing loss of pressure, there have been discussions of this on the wall as more people convert to NG from oil. The drop may be just enough to affect your system and maybe not your neighbors. There are a lot of factors involved.

dbaron

Well if that's the case, JUGHNE, then I will put my new manometer to good use! I imagine it will require quite a few data points to establish that demand in especially-cold periods is driving down my NG pressure.

Jean-David Beyer asked if I have outdoor reset. The truth is I don't know. But I don't think so.

Ironman

The gray box at 9 o'clock inside your boiler is the aquastat. What temp is it set to?

On another note: the plastic vent pipe that was used on your boiler was banned and recalled. There was a corrective action program overseen by the federal government that provided for it's replacement. Last I heard, the 800 number was still active, but no more funds were being given out for it.

kcopp

original post has the boiler set to 200F... and the indirect to 180!
Turn the indirect down to 130....please.
Do the heat pipes run through a crawlspace or an un-insulated area?

icesailor

Must have been a Non-Plumber that connected that indirect tank, and it was never inspected. The Watts N36A Vacuum Relief belongs on the cold water inlet a minimum of 6" above the tank to protect the tank from collapse and vacuum pressure. It does NOT belong on the hot water outlet.

RTFI.

There's one in every box.

dbaron

I think we are getting somewhere.

BobC -- this morning was a good morning to test because the outside temp is back down to 16F, which is driving down the inside temp to below 60. I took several readings (all of which were within a couple of seconds of each other) and the average consumption at the meter was 1:53 for one cubic foot of gas. The boiler was firing continuously over that time. That translates to a consumption of 31.86 cubic feet per hour, which is "off the chart" low (according to the chart you linked to). So, my boiler is not using enough gas. I am not sure what to do about that but I have a manometer coming in the mail in a day or two so that will provide more information.

kcopp - I turned the domestic hot water/indirect back down to 130 as soon as it was clear it wasn't making any difference. Attached are pics of the aquastat (showing 205F), the indirect (showing 130), and the boiler temp and pressure this morning.

dbaron

In case people are concerned about my ability to read meters or do math (all fair enough), what I actually did was time 5 revolutions of the "half foot" dial on my meter - I did that three times and the timings were 4:44, 4:41, and 4:44. I then timed a single revolution of the "two foot" dial on my meter, which took 3:44. That's how I get about 1:53 for one cubic foot.

unclejohn

If you have low gas pressure turn the boiler off now and call a pro who has a combustion analyzer. Your CO is most likely very high.

JUGHNE

A call to your gas company saying "my boiler is not using enough gas and the fire looks funny" (both are true) should ring 2 bells for them: Safety/liability and a meter that could run faster.

Paul48

And they may lock the service and red tag it, at that point.

JUGHNE

Yes, a contractor would/should. But if it is an issue with the gas company supply/delivery outside the house wouldn't they be expected to correct this? His blk NG drop looks to be 1" and the house is not huge. Might they red tag the flue pipe if they correct any pressure issue??

But dbaron, if you get this fire up to 100%, I would suggest lowering your boiler temp down to lowest allowed level and get your flue pipe replaced, probably with stainless steel. As stated above that pipe was recalled. Joints failed and high temps would not help this condition. The C.A.P. corrective action program number 800-619-2265 is still being answered; don't know what they would do for you at this point but might have good info.

And get a good CO detector, maybe one per floor.

JUGHNE

And before it is all over with you probably need a boiler pro for new flue and comb testing.

BobC

I had a problem with fluctuating gas pressure this fall. I called the gas company and told them it seemed my gas pressure was bouncing around. They sent someone over a couple of hours later and conformed my suspicions, they snaked out the pipe going out to the street and that helped somewhat but no gold star.They came back a day or two later and replaced the pipe coming into the house and the gas meter - problem solved.

If you call them they will come, when they are done the boiler will have to be tested with a combustion analyzer. The gas company won't do that, you will need to have a technician do it.

Bob

dbaron

I spoke to my local furnaceman a few minutes ago and he said a lot of people in Boston are having problems right now with insufficient gas pressure, particularly on colder days. He said I might have to raise a ruckus to get the gas company to do anything about it, because he is finding that they are mostly not willing/able to address the problem when it is simply caused by inadequate supply (or cracks/holes in the street pipes). So hopefully my issue will turn out to be fixable at the supply pipe or manifold - otherwise I might have to launch a squeaky wheel campaign to get the problem solved.

Thanks to everyone on this board for their time and help on this problem. I really appreciate it. I will lower the high limit as recommended and get those black PVC vent pipes replaced. I do have good quality CO detectors and they show 0 ppm in the basement and living spaces, but there is no reason to take any chances.

If this discussion remains open I will report back in a couple of days. Thanks again.

wogpa67

Looks like your gas cock is half closed in pic 6 of the first set.

Jean-David Beyer

A year or two ago, the New Jersey Natural Gas company, replaced the main feeder pipe that runs down the street at right angles to mine with a new 5" or so plastic pipe to replace the old 4" black pipe that had been installed in 1950. They also replaced the main down my street with about 4" plastic pipe. That had been about 3". The pressure in all that pipe had been a nominal 15 psi, but was actually about 8 PSI. They had measured it. They now run 50 psi in the new pipe, so I have no gas pressure problems, and I assume my neighbors do not either. Almost everyone on my street originally had oil, and a few still do, but most have converted to natural gas. But more than my street got the new pipe and pressure treatment; it was the entire development involving possibly 10 or 12 streets, depending on how you count them. After the regulator at the input to my meter, the pressure is about 7 inches water gauge.

Before they did this they came out every few weeks to fix yet another leak, and I guess they got tired of that.

JUGHNE

wogpa67, the gas valve question was asked on the first page of the quiz and OP said it was open all the way. The picture is fuzzy and if OP comes back on maybe he could post good pictures of gas valve from both sides. I still wonder about it myself.

JUGHNE

I'm try to figure out how to edit??

JUGHNE

that did not work...then spam block prevents all those multiple posts.

jimyford

Yes, No gas company assured the maintenance of the boiler,we only have to hire the service man.

jimyford

Yes, No gas company assured the maintenance of the boiler,we only have to hire the service man.

dbaron

I took two readings a few minutes ago with my new manometer. One at the inlet pressure tap of the gas controller/valve and one at the outlet pressure tap. Inlet pressure was 8.56 inches WC, which I think is pretty much normal, and outlet pressure was .30 inches WC. I tried adjusting the pressure using the pressure regulator and it had no effect. I thought maybe my barb/tap hadn't set right so I started from the beginning and made sure the inside of the port was clear. It seemed to be. There was also no change in the flame when I adjusted the pressure regulator. Should I just have the whole valve assembly replaced, or can I isolate the problem further? Thanks.

dbaron

Manual says outlet pressure should be 3.5 inches W.C. You all probably already knew that.