My boiler is dead

corey_s

My 36 year old Burnham 2 series has a hole that is not repairable. I've gotten two bids on having a Burnham 3 series installed. The first bid includes the all of the IQ options, but they don't include a new expansion tank or air purge. They said the tank is not needed, but it is the original that was installed 36 years ago. The second bid , which was less than the first, includes an expansion tank, air purge, auto fill, ECM pump, and fancy new thermostat, but not the IQ options. The outdoor reset IQ option is extra. Our system has the old cast iron radiators and big iron pipes in the basement. Some of these pipes are covered in asbestos. I was interested in switching this all to PEX or something similar so the asbestos pipes could be bypassed, cut out, and removed, but they thought It would cost far less to use the same pipes and have a company remove the asbestos from them. I also wanted to add a second zone to our upstairs, but this sounds very costly because the system is not piped for it. They recommended installing thermostatic valves upstairs. Both did heat loss calculations. The first one was 60 @ -15 and the second was 79 @ -16 which seems like a pretty big margin. Both recommended the Burnham model 304 which is a little over sized, but the next smallest model would probably be too small to keep up if we have another Minnesota winter like the last. They both have similar warranties and both have lots of experience with installations. One concern I have is an ECM pump with cast iron radiators. Would it be better if I can get them to throw in a magnetic filter, or just have them install the an old style fixed speed? What other questions should I be asking them? I had no idea switching to PEX would cost so much. Should I stick with the old steel pipes? Is a new expansion tank needed? Please let me know your thoughts. I'd appreciate any advise. Thanks.

Danny Scully

Don’t you know the first rule of fight club? but seriously we don’t discuss pricing.

HVACNUT

The Series 2 was around 36 years ago?
You want to look at Net MBH not gross input.
Being the 304 is 77 net and the 303 is 51 net, I think you answered your own question.
I dont do installations anymore but with residential it's always a complete rip out. Existing pipes cut to the ceiling and all new pipe down to the manifolds. All new parts. Expansion tank, circs, PRV, BFP etc. All new near boiler wiring, relay(s), any low volt splices are hidden best as possible and new low volt wiring to the relay. All new flue pipe to the chimney. Do you have a stainless steel liner? Remove and haul away the old equipment. Clean up nice.

That is a cast iron boiler and you have high water content. Has either contractor mentioned a bypass? I'm not sure if any IQ cards handle condensate protection.
Otherwise the return water temp will cause condensing of the flue gasses and, wait for it... rot the cast iron and put a hole in it.
Pex v. existing piping is your call but if it were me I'd keep the existing and have an asbestos removal company take care of that. You dont need a middle man for that. Make some calls. Its not exactly cheap but it should be done.
I would opt for outdoor reset.
Getting late. That's all I got to give FWIW.

corey_s

Thanks for the reply HVACNUT. Is the EMC pump something that should not be installed on a cast iron radiator system without a manetic filter? Neither contractor has mentioned a bypass. The series 3 is supposed to accept 110 return temps.. I'm not sure how this is done. Does it have a built-in bypass and is this sufficient without the traditional type? Also, what's the opinion of the burham series 3? I'm looking for a work horse that will hopefully last another 36 years. Some of the older posts I've found say it's too complex with too many electronics that will not last. Is that still the general opinion of this boiler?

Solid_Fuel_Man

No interest in going with gas?

Leon82

> @corey_s said:
> Thanks for the reply HVACNUT. Is the EMC pump something that should not be installed on a cast iron radiator system without a manetic filter? Neither contractor has mentioned a bypass. The series 3 is supposed to accept 110 return temps.. I'm not sure how this is done. Does it have a built-in bypass and is this sufficient without the traditional type? Also, what's the opinion of the burham series 3? I'm looking for a work horse that will hopefully last another 36 years. Some of the older posts I've found say it's too complex with too many electronics that will not last. Is that still the general opinion of this boiler?

From what I understand from their website, it's internally piped to accept the low return temp

corey_s

> @Solid_Fuel_Man said:
> No interest in going with gas?

It is gas.

hot_rod

Yes, add a magnetic separation device with any ECM type circ.

The manual does show 110F return? But also deeper in this suggestion. The parts breakdown does not seem to show any internal mixing device.

Steamhead

Burnham still makes the Series 2. Its AFUE is slightly below that of the Series 3, and it has a much more basic control system. It's still a solid boiler that will last a long time. @HVACNUT , you were probably thinking of the Series 4.

corey_s

hot_rod said:

Yes, add a magnetic separation device with any ECM type circ.

The manual does show 110F return? But also deeper in this suggestion. The parts breakdown does not seem to show any internal mixing device.

I'm not sure how they manage to have 110 return temps without a mixing device, but it looks like they still want a bypass installed from what you posted. I don't believe my old boiler had any type of bypass/mixing, but I'm not exactly sure what to look for. Is this something that would cost extra to have it installed, or should I expect them to include it in their bid as part of a proper installation? We do have a large volume system. I also noticed the optional IQ includes LWCO and an aquastat. I thought these were both standard on boilers. An aquastat to regulate the boiler temps and LWCO for safety? Am I incorrect?

Tinman

I wouldn’t trust any cast iron boiler to handle 110 degree return water temps, regardless of what a manufacturer might say. It defies logic.

I don’t see any need for a bypass either.

Use partial reset to protect your boiler.

I love the Series 2. I’ve installed more of them than any other boiler but none in the last 12 years or so. Fell in love with mod cons.

Danny Scully

I think the cast iron is of a different make-up that allows the lower return temps. I’ve chosen Burnham’s x-series boilers for this very reason. They also have a built in LWCO which is nice.

corey_s

> @Steamhead said:
> Burnham still makes the Series 2. Its AFUE is slightly below that of the Series 3, and it has a much more basic control system. It's still a solid boiler that will last a long time. @HVACNUT , you were probably thinking of the Series 4.

@Steve Minnich said:
> I wouldn’t trust any cast iron boiler to handle 110 degree return water temps, regardless of what a manufacturer might say. It defies logic.
>
> I don’t see any need for a bypass either.
>
> Use partial reset to protect your boiler.
>
> I love the Series 2. I’ve installed more of them than any other boiler but none in the last 12 years or so. Fell in love with mod cons.

I didn't know the series 2 was still available. All of the contractors around here seem big on the series 3. I wounder if the added efficiency of the series 3 with out door reset would offset the the added upfront cost over the life of the boiler? I suppose that depends on the price of gas.

Wouldn't a partial reset only allow for a very small efficiency gain vs. full reset with a protection scheme?I rarely saw my old boiler get past 160. Maybe this was measuring the return temps though? What is typically done on these high volume cast iron systems? This is all getting a little over my head.

Solid_Fuel_Man

If you are concerned about efficiency, why not a mod/con? Your high volume, cast iron radiation system would work exceptionally well with one.

bob eck

Cast iron boiler should last 25-30 plus year if sized right, installed right and with proper maintenance. AFUE 84 -85%

Weil McLain has a cast iron boiler GV90 that has a external heat exchanger that gets the venting temp down to where the boiler can be vented with PVC pipe and fittings 90% AFUE


Do you have natural gas?
Does your gas utility or state offer a rebate for high efficiency condensing gas boiler or combi boiler?

The condensing gas boiler or combi boilers are 94-96% AFUE

Condensing gas boiler can last 15-20 plus years if sized right, installed right and with proper maintenance.
Condensing gas boilers love cast iron radiators these type of systems have a lot of water in them and you usually can run this type of system at low water temps.
Find yourself a good professional heating contractor and they can go over all types of systems for you.

You have many choices but a good professional heating contractor will go a long way to keep you warm and with plenty
of hot domestic water for your showers and other needs.

SeanBeans

I wasn’t a huge fan of installing the GV90s.. those flue connections were whack!

corey_s

Thank you for all the responses. I just got another bid from a reputable contractor that is a little lower than the other three. This is for a Weil-McLain Series CGa, Model CGi-4 which looks like it has very good reviews. They only provide a 1 year warranty on parts and labor though. The other contractor I'm considering provided 10 years on the Burnham series 3. Also, they want to use the existing steel expansion tank. Is this an ok thing to do? Please let me know your opinions. Thanks.

Jamie Hall

Is the old expansion tank the really old kind? No bladder -- just air over water? If so, much better to replace it. Probably better to replace it anyway, since it isn't a costly item relative to the rest of the work.

On the reviews. Keep in mind -- firmly -- that a boiler is not a washing machine or a refrigerator. You are purchasing a heating system, not a widget, and whether it works well or not is up to the contractor. Quality installation is what you are looking for.

salio

Don't mean to hijack the thread, but have a similar problem as the OP.
A 20 yr old 133.000 btu Weil Mclain cgi. It is also on a converted gravity system which is what Corey's system sounds like. No bypass piping.
Started leaking two years ago, I pulled everything apart and re-assembled the sections with Permatex (thought the seals looked good and were overpriced - probably wasn't smart). Then this past winter the leaks go progressively worse and finally wouldn't fire at all, so here are my questions:

1) Why don't these things last longer - like 40 years or more? Drives me a little crazy - if my carpentry work failed in 20-25 years it would be ridiculous.

2) I'm trying to do most of the work myself to keep the cost down. Does it make sense to keep the boiler and replace all the sections and seals? It's got a new expansion tank, fan (direct vent) and ignition module. I'm wondering if it also needs bypass piping to prevent boiler condensation?

3) Or do I start over - is the Burnham a better boiler? I have a lead on a Burnham Revolution 144.000 btu boiler for 1/4 the price of a new one that I would pressure test before buying.

Jamie Hall

Depends a bit on where it's leaking. If it's from the seals between sections, then it may be worth taking it apart -- again -- and putting in new O-rings very carefully (it's easy to get them twisted) having cleaned out the Permatex and old seals. Then reassemble using a torque wrench and the correct sequence and torque on the tie bolts.

That is -- assuming that on inspection after the clean up you find that the sealing grooves have not been damaged by the leaking, which is quite possible.

mattmia2

Are these special shaped o-rings or are they just ordinary round o-rings where you could buy viton or silicone replacements that would not age as quickly as neoprene?

Jamie Hall

They're special, both in composition and shape. You cannot substitute a generic o-ring for them.

salio

They're round, but I think they have a square cross-section. Not sure how I would upgrade that design.

Jamie Hall

salio said:

They're round, but I think they have a square cross-section. Not sure how I would upgrade that design.

Correct. Which is why a generic o-ring which has a round cross section won't work. The square cross section is specifically designed to match the groove in the sections and, when properly torqued, seals very well indeed. Either inadequate or excess torque will compromise the seal.

I might add that because of the square cross section, it's remarkably easy to get part of the circle twisted a quarter turn or half a turn. It may look OK on a quick glance, but it will never seal properly.

salio

You're saying it's easy to get the 'square' twisted in the groove? Maybe using a wood block the size of the seal and tapping the entire surface in gently will help prevent that?

Jamie Hall

salio said:

You're saying it's easy to get the 'square' twisted in the groove? Maybe using a wood block the size of the seal and tapping the entire surface in gently will help prevent that?

Indeed it is easy. Your suggestion probably would work. Carefully. And inspect before you start to pull it together. If you're using the OEM part, it won't fall out.