Weil-McLain Ultra 80 series 2 Boiler failed Sunday

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Jadnashua

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Not sure how long it might take, is if you let some of the water in the antifreeze mix just evaporate...you might have less to dispose of. NOw, the stuff can be toxic to animals, so if you have any around you want to keep, it would need to be placed somewhere they couldn't get to it. The issue with Al is that it expands and contracts a lot with temperature change. This can play hell with seals. If things aren't torqued properly, it could overstretch a connecting bolt, and when it cools off, now you have a leak.
 

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Thanks. That is on my list for this summer. My heating guy suggested it.

Actually the stuff in hydronic systems should be (and mine is) propylene glycol. It is not toxic. It is actually used as a food additive. Even with whatever additives are in there the manufacturer considers it non-toxic and the MSDS reflects that. Unfortunately this has not impacted how the state views the material.

I am thinking maybe a little fountain pump and fountain. Spray the stuff from the drum bung into a pan mounted on the drum, drain to drum; repeat. Screen around it to keep critters off. And maybe something to mediate wind drift. Could power it with a small solar panel. On second thought, we have no sun here. Whatever. Maybe just run it down a filter/evaporator mat like a swamp cooler. If it does not clog the media, it would be a lot simpler. I will work something out. Anyone know of a fish that likes propylene glycol? Or how to train a slug to eat it. Them I have a lot of. Or would anyone like some used antifreeze? I would let it go real cheap.

I saw some evidence of your point of expansion/contraction. I had to remove the cover from the heat exchanger for pictures. A couple of the nuts were only finger tight at best. They have a gasket in there, but there was evidence of soot that had escaped around some of the bolts. The entire boiler cabinet is the combustion air plenum, so a bit of leakage in the core would probably not be important. That may be why they did it that way. That was the only area that fittings seemed to have loosened or leaked. And I wonder if it was more of an assembly quality thing than expansion and contraction.
 

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The bolts need to be torqued very carefully. Proper tension on the bolt stretches it a bit, but still within the limits of the expected variance based on the expansion/contraction of the material it is holding (at least in theory). This assumes the proper bolt was specified and it meets those specs. It also assumes it wasn't deformed by over-torqueing it (it can lose its resiliency and be work hardened, causing things to fail). Get this wrong, and it can over stretch the bolt, and it no longer can respond to the material being held together properly. Not getting it tight enough, it will work itself loose. Think of threads as an inclined plane - things will go 'downhill' (loosen) if they aren't deformed or produce enough friction from the proper torque. There's a lot of science in this that isn't particularly critical on some things, but can be disastrous on others.
 

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There was then and continues to be an aluminum specific anti-freeze now more deliberately specified by manufacturers and distributors of the Weil McLain Ultra. I have replaced many Ultra heat exchangers here in Minneapolis. They were all covered under warranty and they all were charged with the wrong antifreeze. Most certainly did not need antifreeze at all unless you think the garage loop will surely freeze up...and the sky is falling.

It makes no sense to me to compromise the pump and thermal efficiency of a condensing boiler for a whole house to safeguard a heated space.

Naturally, snow melting and green houses warrant their own sub-assembly.
 

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Why was anti-freeze installed in the system?
All aluminum heat exchanger boilers require propylene glycol mixed for the purpose.
Small claims.

Your contractor is responsible for the proper application of the boiler and components.
You are responsible for the proper "annual" maintenance of your boiler, which would include testing the pH and correcting any shortcomings. This is especially true if you use anti-freeze in a residential heating system.
 

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I realize this is old, but I wanted to reply to the last couple of comments.

Re: initial antifreeze - it was a product specified by WM. There was some faulty production of the antifreeze. It ate the cores. I had that batch.

The system was designed using the transfer rates with antifreeze. I don't think that reduces the efficiency anywhere in the energy path; it just changes the transfer rate. This, of course, will increase pumping costs.

Why antifreeze? There are 4 areas where freezing is possible Two of them are exposed directly to outside air. 2 have exposed slab edges (Yeah, I know, my bad) and could freeze. The piping make it a real issue to try to install and control isolating heat exchangers for all those areas.

I have changed my mind and will do antifreeze again. WM has recommended a new product (Sentinel) just recently.

Interestingly, with just water I can hear flow noises in some places. Antifreeze makes it quieter. Minimal but useful effect.
 
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Jadnashua

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With less heat transfer per pass with antifreeze, you either run it longer, or you run it hotter. Doesn't make all that much difference except at max load, when you may not be able to get enough heat even when running constantly. But, if sized with that in mind, the only big thing is you may need a bigger boiler than otherwise required. By running things hotter, you can limit your condensing time (the branch doesn't cool off as much per pass), and that can cost more to operate. The pump is in the noise.
 

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Another way to think about it is that for the same amount of heat transferred, the flow rate of the working fluid is higher. So the boiler does not have to change its' operation. Only the circulating pump. Assuming no flow capacities are exceeded. Having a lower intrinsic heat carrying capacity of the fluid can simply be resolved by increasing flow rate. And if you design it that way, it is not a "heat transfer deficit" just design flow rates. This assumes, of course, that everything is selected for the appropriate rates and capacities.

A lower fluid heat capacity per volume/mass does not necessarily imply a change in the heat source parameters or rates of change in the heat sinks. If the flow from the boiler loop to the buffer tank is designed to match the firing rate of the boiler, all is good. And the delivery rate to loops is figured with the known thermal capacity of the working fluid. The only energy cost should be increased pumping cost. With a modulating boiler, a large thermal buffer, and the general thermal inertia of tubing embedded in concrete, and the probability of all loads demanding heat at the same time (except DHW), it is probably not a big cost impact. The controls are smart and regulate how these things work out. I would have liked to have the next generation controls, but the contractor (in a quite rational manner) purchased the equipment as soon as our contract was signed. This was to protect us from price increases. Turned out the construction took quite a bit longer than anticipated and a new generation was introduced before the actual install. I have thought about updating the control system, but it would certainly not be cost effective; cool, but not cost effective. And the vendor added a fourth wire going to the remote sensor/control units; and I have only 3. I should have asked for four just for the possibility of updating, but I just did not think of it.

I am probably (just a guess) losing more energy by having a constant flow circulator feeding the loops with a pressure bypass across source and return that if I had just used a variable speed pump controlling loop pressure as I had intended. That I will most likely correct when someone makes a variable speed pressure sensing pump that is quiet and smart. To date, all possible suitable pumps I have found are way to high capacity for this system to sit anywhere rational on their performance curve. The people making pumps do not seem to have grasped the concept that a modern well insulated structure of significant size (mine is 6K sf ft), simply does not require the flow rates of what they view as "residential" pumps. They still make pumps for 1950's houses that leak like a sieve and have 400KBTU boilers that run a lot.
 
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