Sorry, Denton, Master Plvmber Still Smells A Rat
Denton, the kudos may need to get revoked. I am reposting because I want to bring this back to the level of Present Problem That Needs Solving, instead of the “Denton Was Right” post, which is about thinking that there was a solution. Master Plvmber and CMU think that the plumber I consulted was wrong,…
Denton, the kudos may need to get revoked. I am reposting because I want to bring this back to the level of Present Problem That Needs Solving, instead of the “Denton Was Right” post, which is about thinking that there was a solution.
Master Plvmber and CMU think that the plumber I consulted was wrong, and that the facts of the “Denton Was Right” post are muddled. Which they are. I was mostly in it to congratulate Denton.
Here’s what I can clarify for MP and CMU and anyone else who knows a thing or two about boilers. If you’ve all got time, I would definitely like to get a sense of whether this plumber I spoke to was on the level, or in the ballpark:
ORIGINAL PROBLEM:
High gas bills in the middle of summer and beyond, with boiler firing often. High gas bills started after installing indirect H2O heater and hydronic radiant heat to the boiler that came with the house.
Boiler in Question: a weill-mccann (sp) that is, according to the plumber I met with last night, “84% efficient.”
Troubleshooting steps taken so far:
*Turned down temperature to 120 for awhile, this worked to lower the bill, but didn’t make showering very fun. I do like a hot shower.
*Made sure the heat was off
*Listened to the boiler closely for awhile and just made sure it was firing when it was supposed to. It seems to be firing after showers and such, and not you know, at random, now that the temperature is set to a reasonable 125.
Met with a plumber last night. Here’s what happened:
1. The plumber confirmed that there was no leak, but not by testing anything. He basically said that if there was a leak, we would all know because we would smell it.
2. He said that there was nothing wrong with the way the system was set up. The thermostat on the water heater is set to 125. He looked at the way everything was set up and definitively said that the problem was the boiler.
3. He said that the existing boiler was like 84% efficient, and that additionally the bottom of my boiler was “open” and pointed to the open vent area at the bottom, and that a condensing boiler would be a “closed” system that isn’t always drawing cold air. He did use the terms “open” and “closed.” He also talked about the basement being relatively chilly. I stated that the highest bills I’ve had so far were in June and July, but he kept going, explaining cold drafts, and etc.
Okay, now I am starting to feel a little dumb. But I’ll keep going.
4. He said that the big difference wasn’t just the 84%-95% difference, but the idea that the flame modulates. He said that hooking up an indirect tank to a non-modulating boiler is a recipe for a high gas bill, because you shouldn’t be using all your BTUs to cook a little hot water.
5. He also suggested that I insulate my pipes.
There are no 40 minute showers, very few baths, our *water* bill for the last quarter was only $60. The heat hasn’t been on all summer, I can’t figure any other place to start thinking about it.
Obviously I am going to keep interviewing plumbers, seeing as how the trusted and knowledgable MP has given up on the good people of Bed Stuy ; )
And what I am hoping sincerely is that you guys are right, and that there is something going on that isn’t a new boiler. It’s not the right economic climate to buy a new boiler.
You may have already solved this problem, and I’d be interested to know the root cause. I will be in the same situation when I move into the house I just bought: an older non-modulating boiler in the basement supplying baseboard heat, and an aging hot water heater that I aim to replace with an indirect. Even if the boiler is non-modulating, I think it remains viable because baseboard heat requires 180 degree temperatures, same as what an indirect water heater would require from the boiler.
From your posts, I cannot tell if your using a domestic coil in the boiler to feed the indirect water heater. From what I’ve gathered, this is not efficient. The indirect water heater should be its own zone with a different temperature requirement than your radiant zones.
You might also want to check the circulation pump. One of the better articles I’ve come across is one that talks about correctly sizing the indirect water heater and the circulation pump.
http://contractormag.com/columns/yates/boiler_indirect_water/
A wrong-sized circulation pump could lead to performance problems.
Sorry, hit the post button leaving a dangling colon:
What you are saying about the pump is not greek to me, but I am not sure you are just talking about steam boilers.
There is a relay, I am pretty sure, that makes the H20 tank communicate directly with the boiler, so that the pump only runs when the tank demands it. I can confirm this if it helps, but I am not sure whether you’re talking only about steam.
Thanks for the advice!
Sorry MP, it’s a hot water boiler. I was being vague. We didn’t want to turn up the temperature too high on the hot water boiler because it would be bad to make steam with our hot water boiler.
If turning up the boiler temp isn’t the problem then I’ll turn it back down again.
The heat’s not on yet, it’s been really mild and the house is still plenty warm. The problem is the relationship between the hot water tank and the boiler.
What you are saying about the pump is not Greek to me. I am familiar with the system:
I see, a bacteria problem. I do have a mixing valve like Denton, but here’s the thing: when my water tank was set to 140 degrees, my gas bill was $190 a month. Turning it down to 125 almost halved the gas bill–from $190 to more like $100 even.
VBP, did you mention earlier that you’re heating a radiant floor and an indirect water heater with a steam boiler?
It’s really easy to do that wrong, and it’s wrong to do that easily.
That installation needs a relay to isolate the boiler’s burner and allow the pump only to run on call from the tank.
I know that’s probably Greek to you, but I see installation after installation like this where the boilers are set to maintain a minimum internal temperature and the indirect just turns the pump on.
I’ll bet that’s your problem.
Some other quick thoughts:
1. Denton probably sets his hot water heater temperature to 140 degrees because he knows that below that temperature is where bacteria like Legionella start to thrive.
Follow his example and turn yours up, too.
2. Turning your steam boiler up from 180 to 190 will definitely increase your fuel usage.
3. The radiant heat zone needs to be monitored at the supply and return pipe connections to determine the difference in water temperatures at those points. That information will help determine how many BTUs are being lost to the floor.
Hey all, I went downstairs and have this to report:
LH: the boiler was set right at 180 degrees. DH and I went back and forth a little bit about not wanting to make steam, and bumped that thermostat up to 190.
We also just doublechecked the connections and poked around, confirmed with our noses that we have no gas leak, and looked at the meters, which are not running or anything.
Friday I am going to HD and buying pipe insulation, Denton. I know, you’re right. There’s just so much to do…
I am also seeing another plumber on Friday.
Tomorrow I am starting my siege on National Grid, nee Keyspan. Honestly, right around the time all this started I started using online bill pay, and I feel foolish, but I can’t even successfully log on to National Grid and see my bill right now. Not a firm footing to start on, but fixable.
Mopar’s suggestion is a good one.
Of course, I’ll keep sharing.
You definitely need to listen to MP over me. But all i said was you should get a new boiler.
A mod/con boiler has specific intake and exhaust requirements, both of which can be found on boiler mfgr’s websites. But in all cases they will take air from the outside, not the basement.
The plumber is right, you should insulate every inch of copper tubing you can, both cold and hot. If you don’t insulate the cold you will get condensation and dripping. It’s obvious why you have to insulate the hot! If you haven’t done that all this other efficient stuff is a waste.
You should have your tank set at 140deg F, imo. There should be a valve to limit what goes upstairs that you can set. I’m pushing the envelope of my knowledge here, in fact maybe exceeding it, lol. But I think LH is right about maintaining a difference btw boiler vs. tank. My tank sends water upstairs at 125degF but is set at 140degF. Therefore the boiler doesn’t kick on until the tank drops to 125 degF and it brings it up to 140 degF. Remember that an indirect tank, if no water is used, will only drop a coupla degrees in 24 hours.
And who knows, maybe Mopar has a point?
Have you called the gas company to see if the meter is reading correctly? I had absurdly high heating bills in the summer and after telling me repeatedly that this was normal, the gas company sent someone out to check the meters and sure enough, the outside meter was double the inside one.
Usually an “open system” is one where the water that is used for heating is interchangeable with the potable water in the house. This is the most efficient heating/hot water system, however an “open system” is not to code in NYC. What your plumber is talking about is an “open vent system” on your current boiler as opposed to a using stainless steel modulating gas fired condenser. But this is expensive and I don’t think you have to pony up for that right now.
You mentioned that you have set your indirect water heater to 125. However, what is your boiler temperature set to? In order for your boiler to heat the water in your indirect hot water tank it should be set to at least 180. If it is set much lower than this your boiler will short cycle causing high gas bills and high electric bills since your pump will be on all the time.