25-year old Burnham Series 2, Model B Boiler: Parts and reliability possible for another 10 years?

rossn

Have a 1999 Burnham Series 2, Model B cast iron boiler... with the remodel tightening up the home, have a few challenges around combustion makeup air and moving from a high temp system to a Mid + low temp hydronic heating system. Would prefer to hold off on replacement, but not if I can't practically get another 10 years from it.

- Is it practical to think I'll be able to get parts for it for another 10 years?
- With this particular age and series of a boiler, is another 10 years of life without ongoing issues reasonable to expect? I will say I have done very little service in the 8 years I've owned the home

Steamhead

Shouldn't be a problem. The Series 2 boilers are well designed and use mostly standard parts. As long as it's not leaking I wouldn't suggest replacing it. Just make sure it's piped properly for a low-temp system.

EdTheHeaterMan

Agree with Steamhead. You will want to look in the manual for the low temperature piping options recommended by the manufacturer. The basic idea is to have the boiler return water above the point where flue gas condensation will cause a problem with corrosion of the cast iron. Some say that is 140° others use 135° return water temperature.

Looks like Burnham offers a kit to solve just this problem set at 120°.

JohnNY

I don't like the motor position of the pump in that diagram.

EdTheHeaterMan

JohnNY said:

I don't like the motor position of the pump in that diagram.

I didn't print the instruction manual. But I agree if that is an elevation diagram. But it would be perfectly acceptable if that is a floor plan diagram. The actual photo is what is included in the kit.

Mad Dog_2

I can't think anything that proprietary to that boiler that you won't be able to get parts in 10 years.  Going foward, especially that you'll be running lower temps through it, Do your annual maintenance.   Mad Dog 🐕 

rossn

Hi All,

Thank you for weighing in. It sounds like most likely, I could get by for another 10 years or so, possibly with some higher maintenance costs and slight risk that very few of the parts may be proprietary and not available. I have a massive remodel going on, of course every extra $10k adds up, and would prefer to get through the remodel before committing to replacement. If I went forward now, I figure I would recoup (with taxes, fuel savings, and other offsets) about 1/3 off the price of a new viessmann install, so it is a tough call for me.

Moreso, by biggest issue currently is that with the tightening up of the home (I'm the GC on the project), is I am going to have to introduce combustion makeup air either by 2 large (8", if I recall correctly) holes in the wall on the opposite end of the utility room (ducting is challenging given sizing and electrical panel placement), which would draft across the indirect hot water heater, all the plumbing, etc.... not ideal. The alternative being putting a hole in the wall next to the boiler to commute with the larger space of the home, but I will say that it (and especially the Belimo control on the mixing valve) are quite loud. I also checked with US Boiler, and they confirmed that my series does not a have a way to introduce makeup air directly to the unit (bummer!).

As to the comments about maintaining the minimum return temp... I'm taking note of that. The current system was setup for high temp + mid temp with mid-temp being on a mixing valve. Now that we are adding radiant floor for 60% of the home, it's transitioning to mid + low temp. My radiant guy was suggesting we set the boiler to 140-150 temp (the initial design I put together for the medium temp requires 130 AWT @ 1F with a deltaT of 20) for the mid-temp and re-purpose the mixing valve and outdoor reset for the low temp zone. In that case, would I still need the additional bypass pump kit? Either way, I'm not sure how much less efficient I am by having the other 40% of the house run at boiler temp (140-150), versus being on a mixing valve with outdoor reset to run at lower temps most of the year. Here we are using heating about 8ish months each year with 1 degree F design temp.

Many thanks for the input above... that is really great information for me.

mattmia2

Since it is not a condensing boiler you need to keep it hot enough not to condense. i wouldn't go below 150 for the setpoint and mix down for your lower temp zones where needed. The radiant needs lower temps, most other emitters will just run shorter cycles at higher temp but it won't damage anything.

mattmia2

And you still need some form of low return temp protection, either the variable circulator or a thermostatic valve because the radiant will have low temp water coming back.

oh, and please edit to remove prices, pricing is not allowed

Mad Dog_2

I would repipe the existing boiler, take good care of it and run it to failure....that could buy you 10-15 years.  Don't chuck a workable workhorse.  Mad Dog 🐕