Problems with Older Hydrotherm Boiler (gas fired)


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Old 02-14-12, 02:59 PM
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Problems with Older Hydrotherm Boiler (gas fired)

A few months ago, I noticed that when the boiler kicked on, it was much louder than usual. Then, about 10 days ago, the CO2 detector in the boiler room went off during the night.

I called the gas company first and had them check for leaks. They didn't find a problem so we had the repairman come out. He thoroughly cleaned and examined the unit and also cleaned the flue/chimney. Things seemed ok until today, a week later, when suddenly the CO2 detector went off again.

What could the problem be? The boiler sits in a room in our basement and there are three open wall vents going into the room. Nothing has changed around the house that would cause a decrease in the amount of fresh air available to the boiler room. The repairman said that there is the correct amount of pressure going to the unit so he doesn't think it's the gas valve.

I'm desperate for any other suggestions as to what the problem might be. We already ran up several hundred $$ in repair costs (but that's a whole other story) and don't want to pay the plumbing company more money only to have them not be able to find and fix the problem.

Thanks for any help you can provide.
 

Last edited by NeOrKate; 02-14-12 at 03:00 PM. Reason: to change notification setting
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Old 02-14-12, 03:11 PM
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Whats the model # of the boiler?

Did the repairman remove the burners and clean them? Did he remove the flue and stick a bristle brush to clean between the sections?

Mike NJ
 
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Old 02-14-12, 03:22 PM
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Have there been any hints from these repair people to the effect of:

"Well, it's time for a newer more efficient boiler", etc ? I'm wondering if they perhaps have a vested interest in NOT fixing it?
 
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Old 02-14-12, 03:32 PM
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lawrosa - I'll try and get the model number. I'll have to find a magnifying class in order to read it

NJ Trooper - so far the repairman hasn't hinted at that. The tech from the gas company said that it appears to be in Ok condition for it's age. My husband asked if we should think about getting a more efficient boiler and he replied that it probably wouldn't pay to do so.
 
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Old 02-14-12, 03:36 PM
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Take some pics if you can. Always good to see it.

Post to a free site like photobucket the post the link to those pics here.

Mike NJ
 
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Old 02-14-12, 03:47 PM
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Good... sounds like they are being honest with you! That's a rare treat these days!
 
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Old 02-16-12, 10:59 AM
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[IMG][/IMG]

Here is a photo of the boiler. The model number is HC 145
 
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Old 02-16-12, 11:04 AM
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It seems that there is no CO2 detected until the boiler has been running for awhile. If its totally cold, it takes about an 1 1/2 hours. If its warm, it takes about 15 minutes. It's been as high as 38ppm but then we shut it off. Using smoke, we have tested both the draft from the boiler and the hot water tank and it seems to be OK (both hook into the same flue).
 
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Old 02-16-12, 11:24 AM
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OK. Similar to my boiler. cast iron burners like mine, nice.

Those burners should be removed and the boiler cleaned properly. The draft hood of the boiler needs to be removed. Then a long pipe cleaner type brush needs to be inserted between the sections. Then thoroughly vacuumed.

Make sure the burners go back together properly.

Not liking the gas line going directly in the top of the gas valve with no drip tee. This was common install on these and often sediment gets inside the gas valve which may cause CO issues.

Also the flue shares the water heater is OK if all is sized correctly. If masonary chiminey I would absolutly check for tiles that may have fallen and blocking the vent passage.

Same water heater? Proper Y connection to the main vent and not some homemade tee?

Also those air shutters on the front of the two round burners should be open all the way. I cant tell by the pic if one is closed or not.

More pics at various angles is preferred.

Also how old is the CO detector? They need replacement like every 5 yrs.

I would suggest its not really something to mess with and you should pay a plumber with a combustion analyser to clean and test the levels properly. If your repair man did not do this he is doing you an injustice.

You know the old saying "you can wake up dead" !!!

Mike NJ
 
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Old 02-16-12, 12:23 PM
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We opened them both up - they weren't open all the way



this is the top of the gasline - is this what you mean by it should have a drip tee?





here is the set up for the water heater and boiler ducting.

Thanks so much for helping us out. We really appreciate it. Last week when the plumbers came over they took it all apart and thorroughly cleaned the boiler and the chimney (there was some debris in the chimney which they cleaned out).
 

Last edited by NJT; 02-16-12 at 03:32 PM.
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Old 02-16-12, 12:39 PM
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So, we turned it back on after opening the air shutters. !5 minutes later the CO2 was reading 35.
 
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Old 02-16-12, 12:43 PM
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Yeah not likeing that tee for the water heater. Is that duct tape on one of the joints...uggg!.

Your reall need a combustion analysis done. The boiler needs to be under 100 ppm I believe.

Next water heater you need a low boy so it can be hooked up with a proper Y and proper pitch.

Could it be the CO is back drafting through the water heater flue or the water heater itself?

This is where a combustion test will find the cause.

Saftey should be your first priority. espeacially with children. Low levels of CO cause developmental issues from my understanding.



Mike NJ
 
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Old 02-16-12, 12:55 PM
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We just put the duct tape on it yesterday because we noticed the connection wasn't sealed. Just a temporary fix until we get some metal tape today. As for the water heater vent - are you saying that the vent pipe from the water heater should not be straight across like it is?

Fortunately, we don't have any kids in the house and we aren't running the boiler except to test it after we tweak something.

Can you be more specific about the combustion test and the boiler being under 100ppm? I don't think the plumbers did a combustion test - I'll find out.

The thing that I don't understand is we have had this setup this way for over three years - why would it suddenly start acting up?

The CO2 detector we had in the room is about 2-3 years old. We did go out an buy a CO2 monitor with a digital read out so we could track the high and lows.
 
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Old 02-16-12, 01:03 PM
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Where the water heater connects to the flue for the boiler needs to be a Y and not a homemade fitting like you have.

A combustion test has a snuffer they insert in a drilled hole before the draqft hood and after. They can tell what appliance has high CO levels. Oxygen to fuel ratios, CO2 levels ect... And possibly find the corrective action in the process.

Mike NJ
 
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Old 02-16-12, 02:07 PM
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As far as we know, the water heater connection has always been this way. The plumbers put in a new water heater when we remodeled (about 3 1/2 years ago) but they just used the existing connection. Right now, the water heater is running and the boiler isn't and there is no detectable CO reading. So, are you saying that we should have a Y connection that is the same size pipe as the rest of the pipe?

What do you think it will cost to do a combustion test? Where we live we only have two options for boiler repairmen and, seems to me anyway, things always cost WAY more than it seems like they should.

Thanks again, Kathy
 
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Old 02-16-12, 02:30 PM
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What do you think it will cost to do a combustion test? Where we live we only have two options for boiler repairmen and, seems to me anyway, things always cost WAY more than it seems like they should.
Hmm whats your life worth???


IDK say $200-$300

Water heater should be 4" flue. Then the Connection where it connects in the main flue should be, looks like to be a 6x5x4 Y.

Here is what a combustion analyser will read.



I had a 280 co reading on my old hydrotherm. They cleaned it and got it down the above. I did not believe them and had a independent person come out to check. Needs to read under 100 ppm. I am at 7 ppm. ( Although I still dont believe it...LOL)

My 1984 Hydrotherm with powerpile.




Mike NJ
 

Last edited by NJT; 02-16-12 at 03:29 PM.
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Old 02-16-12, 03:27 PM
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We opened them both up - they weren't open all the way
So, we turned it back on after opening the air shutters. !5 minutes later the CO2 was reading 35.
WHOA! back the truck up!

You absolutely should NOT have touched those air shutters!

Those are to be adjusted only when one has a COMBUSTION ANALYZER to set them properly. They are not 'supposed' to be 'open all the way' ! They are to be adjusted to provide the proper air to fuel ratio for proper combustion. They can NOT be adjusted 'by eye'!

To quote a wise man:

Hmm whats your life worth???
 
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Old 02-16-12, 03:37 PM
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why would it suddenly start acting up?
Stuff happens.

I'm also nervous about the proximity of those flue pipes to combustible materials. By code, there is supposed to be EIGHTEEN INCHES of clearance from a flue pipe to any combustibles. Shame on the person that did that work. That's just plain reckless.

Where does that flue pipe go after it passes through that wall?
 
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Old 02-16-12, 04:09 PM
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Yeah those air shutters were halfway previously. You can easily turn them back if you like.

But given servicing and adjustment practices in years past, it probably wasn't important to adjust the air shutters and more then often they were opened, no?

Which the fully-open setting was "probably" always used, but I am sure it will be debated. If it was an erroneous setting, it erred on the side of caution I would think. Isnt it benificial with the absence of measurement equipment?

The air shutters probably should be adjusted but I have yet to see techs adjust them on gas boilers during service.

Possibly condensation issues or soot.

What type of heat emmiters? rads, baseboard?


Mike NJ
 
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Old 02-17-12, 04:49 PM
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Hey- thought I'd let you know that we might have a diagnosis - but unfortunately it might mean we have to get a new boiler. I talked with a guy who's been working on them for 50+ years. As soon as I got CO2 out of my mouth he told me he knew exactly what the problem is. Seems there are rope gaskets in between the cast iron sections. He said they have probably deteriorated and that it would probably cost as much as a new one to repair. Any thoughts?

Oh, by the way, we did reset the air shutters once we realized opening them up didn't change anything.

So, if we do have to get a new boiler - any thoughts on switching from gas to electric? Where we live electricity is a bit cheaper than gas - but then there is no guarantee it will stay that way.
 

Last edited by NeOrKate; 02-17-12 at 04:53 PM. Reason: add text
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Old 02-17-12, 05:13 PM
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He said they have probably deteriorated and that it would probably cost as much as a new one to repair. Any thoughts?
I wonder if the seams were pumped full of high temp silicone if it would buy some time.

Peter
 
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Old 02-17-12, 05:24 PM
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any thoughts on switching from gas to electric? Where we live electricity is a bit than gas -
wow electricity is 15 cents a kilowatt around here.

How much is it there?
Is there hydro generation that keeps the price down?
The appeal of electric is the near 100% efficency.
Plus it is reliable with very few parts to go wrong.

Peter
 
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Old 02-17-12, 05:28 PM
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Where does that flue pipe go after it passes through that wall?
I'd still like to know the answer to this question.

When the guys took down the flue pipe to clean it (you did say they did that, right?) Did they properly seal the connection into the chimney? I mean, there must be a chimney on the other side of that wall, right?

A combustion test is still in order here... if your boiler is producing thousands of ppm of CO (not co2 by the way) then there is something wrong with the combustion! If they are unable to lower the CO levels, it may lend some evidence that too much excess air is coming into the system through leaks in the boiler and such.

You can GUESS all you want, it's your home, and your life.
 
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Old 02-17-12, 07:39 PM
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Peter - we get our electricity from a co-op (which buys the power from the Bonneville Power Admin) and yes, it's hydro. We pay about 7.8 cents a kWh.

NJ Trooper - didn't mean to ignore you about the pipe - just forgot to answer in my last post. The pipe goes into a chimney on the other side of the wall. So, by combustibles, are you referring to the floor joists and other exposed wood? If so, how do we correct that?

I asked the plumber about a combustion test and he said we didn't need one and talked about atmospheric boiler vs sealed boiler. I don't really understand what he meant by that.
 

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Old 02-17-12, 08:12 PM
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I asked the plumber about a combustion test and he said we didn't need one and talked about atmospheric boiler vs sealed boiler. I don't really understand what he mean by that.


IMO you should probably find a new plumber/boiler man.

I talked with a guy who's been working on them for 50+ years. As soon as I got CO2 out of my mouth he told me he knew exactly what the problem is. Seems there are rope gaskets in between the cast iron sections. He said they have probably deteriorated and that it would probably cost as much as a new one to repair. Any thoughts?




Read below. Those gaskets seal the sections together. If they were bad you would be leaking water. I think they have nothing to do with the CO level.

Are you letting the boiler get up to temp, or are you taking these readings as soon as it lights? The flue on any boiler needs to heat up some to start drafting properly. What type of heat emitters do you have??? You never said? And you did not say if he brushed the inside of the boiler and cleaned it properly? We are trying to help but your not giving answers the pros need here.

Why Cast Iron Boilers Leak

But anyway if you got the $$$ yeah replace it. By the time you fix the flue thats all taped up, and fix that water heater tee, have a combustion test done etc... you may be into close to $1000 from a pro.

Myself I would not go electic. Looks like you have three zones there. Best to have a heat loss done of the home and size the new boiler correctly.

I would get other estimates. IMO I am not liking the attitude of your plumber, but who knows? "He might be the best thing since sliced bread"!!!


Like was said before its your home you can do what you want.

Mike NJ
 
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Old 02-18-12, 08:02 AM
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The pipe goes into a chimney on the other side of the wall. So, by combustibles, are you referring to the floor joists and other exposed wood? If so, how do we correct that?
And where the pipe enters the chimney... is it 'grouted' all around? Or is it just stuck into the hole with gaps all around the perimeter?

Combustibles = anything that can burn. So yeah, wood, paper, etc... The pipes would need to be moved away from the combustibles, or the combustibles moved away from the pipe...

OR things called 'radiation shields' would have to be properly installed. There is also a type of vent pipe called 'double wall' that reduces the clearance requirement to 6" I believe.

This article while specifically geared toward wood burning appliances has some good information and it all applies to ANY flue pipe.

http://www.homepro.ca/newsletters/WETT/4shields.pdf

he said we didn't need one
In other words:

1. He doesn't know how to do one.

2. He doesn't have the equipment to do one.

3. He doesn't want to do one.

4. He is ignorant.

Here's the thing... you've detected CO levels that are way too high in your living space, that's a given.

That CO is coming from somewhere, and leaking into your home, another given.

The SOURCE of the CO needs to be found and corrected, FIRST. If your boiler or water heater is producing thousands of part per million of CO, it's nearly inevitable that some of that will leak into the home and give elevated levels.

If your appliances are only PRODUCING much smaller levels of CO, then it stands to reason that even if there were a leakage path, the levels in the home would be much lower.

After the SOURCE of the CO is found and corrected, then any leaks in the flue system would need correction. It's a two step process.

How about an analogy?

I had a dead mouse in the garage. Stunk to high Heaven. I sprayed three cans of Fabreze around. It still stunk. I found the dead mouse and disposed of it. It didn't stink anymore.
 
 

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