Buderus Wall Mount

Grumpyplumber

I have a customer who wants a Buderus (gb 142) wall mount condensing boiler (direct vent)...I've researched them and I'm drooling, almost 96% AFUE.
The price is very competitive to Burnhams condensing boilers, minus the stainless vent you have to purchase.
I was told they've been around for years in Canada...plus they come with a lifetime warranty to top it off.
Wondering if any of you guys have done one?
Any thoughts on the pro's and cons?

PIPES

They are wonderful units to install and service. The only issue I have , if you are running high temp system only (baseboard/ indirect) your eff. is only in the high 80's not the 96 they advertise.

Grumpyplumber

If thats the case I'm gonna scream!
The gas co is offering a sizeable rebate based on the fact that this unit runs at better than 90%...I'm supposed to pick the unit up in the morning.
Before I head to the supply, I'm calling buderus.
Thank you for the skinny on that...mighta just saved me a big headache.

Grumpyplumber

Well, the verdicts in...just off the phone with 'em and I got the details.
They "accidentally" forgot to include that detail in their advertising and in the installation manual...tech guy explained that the efficiency drops as low as 89%, depending on operating temperature...the optimal operating temp is 130.
Condensing boilers are pretty much all that way, the higher the operating temp, the less it's ability to condense.
At 180 degree's the efficiency is 89%, it appears the efficiency changes by approximately 1-1/4% or so, per ten degree's operating temp. (I'd wager the ratio of % vs temp isn't as neatly distributed as that though)
The unit still qualifies for the rebate, which is a major factor in the decision to install it.
"Pipes", again, Thank You

PIPES

Always happy to help, have fun with the install. If it's your first , read the book and read it again before you start.

Grumpyplumber

Already have....You'll laugh when I tell ya this one.
After reading it (some 64 pages), I called the tech support guys to ask specifics on the air/gas manometer test, they tell me it's crucial that I run a test to make sure the ratio is perfect and I'll need a digital manometer that measures within .01, both positive and negative...spent 3 hours calling every supplier I could find to see if anyone has one and got the same answer each time "We have mercury tube manometers...but nobody ever requests those type", all the while leaving messages with field tech support to see if they know where I can get one locally.
finally a supplier gets back to me with one he's having shipped in tomorrow.
5 minutes later, a company field technician calls me (hands on guy)..."I got your message....why are you looking for one? This is a new install....they're calibrated at the factory."
He told me it can't hurt to test it and a combustion analysis would be a good idea too, but not crucial...he said "I've tested hundreds and seen maybe one that needed adjustment."
Well, I'm going to take the 45 minute ride tomorrow to pick up my prize...then I'm going to test the unit ...and test ...and test.

mdshunk

Is there any particular problem with running your convector loop a bit closer to 130? I suppose you'd be sacrificing some delta-T at the end of the loop, huh?

Grumpyplumber

Baseboard + Indirect water htr = not good at 130

Standard domestic hot water is 130, maybe less depending on homeowners taste...the recovery time on the indirect would be slow. (45 gal superstor)
Then...the nominal operating temp for standard residential baseboard is about 180...imagine you leave the door open to bring in groceries in mid january...

This system is best for radiant floor heating, where the temps aren't so high, but the tech guys tell me it's still ok for what I'm doing, though there'll be some AFUE% loss.
May have to tweak it in the winter to find a happy medium though.
Also comes stock with an optional outdoor temp sensor to help the boiler run more efficiently in the warmer months.

Grumpyplumber

Well, it's all good...fired her up today...asked the homeowner to come down so I could go over the operating details.
It was running at full capacity to reheat the indirect...the homeowner takes a look, then asks me "So...you gonna start it up?".
After explaining that I already had, he says "My hairdryer makes more noise!".
One heck of an impressive unit, open the case and everythings right there - easy to access, though the operation can be a little confusing with the digit readout...I hope to install more.

Grumpyplumber

Thought I'd follow up on this.
I been getting periodic updates on the customers gas bill...excellent results.
He saw an immediate difference on his indirect hot water bill last summer (DHW) at about 30% less CCF's.
The heat bill went down quite a bit as well.
All in all, Buderus...not bad.
Makes me look good when a customer is happy he spent the extra money.

Bob Walsh

The comprehensive range of 'heat-only' boilers deliver very high levels of energy efficiency and reliable performance year after year. Each boiler is a rated and has ultra-low (Class 5) emission levels. Fully modulating fans and burners ensure maximum energy savings and precisely match output to the heat demand. All regular boilers are compact and lightweight making them a great choice for replacement installations as they fit quickly and easily into existing heating systems. Each boiler comes with a 2 year parts & labour warranty as standard and a 5 year heat exchanger guarantee.



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