Inefficient Boiler

John_61

I had my 40 year old boiler replaced 2 years ago with a brand new 85% effiecient Utica boiler, and I use more gas than I did with the old unit. The house has baseboard convectors.

The install was a little confusing to me, the outlet was plumbed directly to the inlet with a pump, and all 5 zones had their in AND outs into this "manifold" with their separate circulators. Is this a good way to plumb it? I know prices have gone up but I use more cubic feet than I used to.
Any suggestions?

hydronicsmike

it appears...

...those zones are piped in primary/secondary which is acceptable.

Are you using Outdoor Reset at all? It could reduce your fuel consumption by up to 30%.-see attached

Mike

Mitch_4

how

did they size the new boiler? look at the old rating plate and use the same input? was a heat load calc done. Oversix=zing any heating equipment WAy too much will kill ANY efficincy.

If it doesn't run long enough it never reaches steady state.

Your old boiler may ahve been 60% efficient by modern stds. your ne onew is 85% if your heating contractor did same input method. on a 100,000 unit that 25,000 more heat into your home. or a 29% increase in capacity vs your old boiler.
( I am using 100,000 for ease, you didn't state boiler size)

asta la vista savings.

Need more info
Mitch

Plumbob

> the outlet was

> plumbed directly to the inlet with a pump, and

> all 5 zones had their in AND outs into this

> "manifold" with their separate circulators. Is

> this a good way to plumb it?



Yes, this is primary/secondary pumping---a good thing.

As for why you are seeing an increase in usage, it must be something else. You don't say how much increase in usage. While comparing cubic feet is better than comparing dollars, even cubic feet consumption can vary because the weather varies. The fact that you are comparing cubic feet suggests that you have saved your old bills. If your gas bills list the degree-days in the billing period (the degree-day total is a measure of how cold it was), take bills for the same month (say January) for some year before and some year after the boiler change, and divide the cubic feet by the degree-days. If that ratio is smaller with the new boiler, you have an increase in efficiency. That is the only reliable test.

Of course it is possible that there is a decrease of efficiency due to a boiler problem or installation problem, but first do the calculation as described above so it is not just a feeling you have.

PS Is your new boiler even bigger (more BTUs) than the old boiler? That would be one reason for an efficiency decrease, just as a big car is less efficient than a small car.

Weezbo

Hello.

let me ask ,did you renovate any ceilings walls ,windows or doors, in the process of installing the new boiler? Did you change the flue out at that time for some new B vent? have you checked to see if you might have a leak in the gas line?