My New EK-2 Boiler Isn't Meeting Efficiency Expectations. Any Help Appreciated!

wjcandee

Three months ago, I had an EK-2 Frontier boiler with an 80 gal DHW tank installed by a Premier Dealer here in the Northeast. It is only running 22.5 percent better than what it replaced, which was a Bock 50ES oil water heater and a 100-ish year old gigantic asbestos-covered oil water boiler with ancient Carlin burner with 2 nozzles at 1.75gph each, which maintained 140 degrees 24/7/365 because we at one time used the coil and nobody dared turn it off in summer for fear that a turnoff would induce leaks.

Our neighbor replaced basically the same boiler and setup with a Weil-McLain Gold series for less money, and it is claimed that he saved over 35 percent. So the EK should do as well or better, but based on 8 years of degree-day/consumption data meticulously kept on the old boiler, the new boiler savings doesn’t even come close to 35 percent. The salespeople were talking 40 percent, but that now seems completely out of reach, very-dramatically-changing the financial calculations we made about the payback period for the investment.

We have two large hydronic zones feeding cast-iron radiators in a 5500-sq-ft old house. We have the high-mass-low-mass kit, and so we have a primary loop, and two injection loops through zone valves, which loops send part of the return flow through the EK mixing manifold, which receives and blends bypass water from boiler output side of the Flat Plate Heat Exchanger (FPE). The ball valve is full-open. The burner nozzle in the Carlin EZ1 is the default one. The thermostats are set for no more than 2 calls per hour, and I have been told that the draft and chimney are perfect.

The Premier Dealer that installed our boiler made a number of obvious installation errors that it has partially corrected, and they (re?)tuned the burner with a combustion analyzer and tell me that they thereby improved the burner efficiency by 5 percentage points. But they now claim everything about the installation is as it should be, and yet the efficiency isn’t what it should be, I think.

I have been videoing the boiler in operation, and I notice one thing that seems odd. Because we have large secondary loops with tons of cool water in them, the hydraulic operation of the system obviously depends on significant bypass water to temper the return water and prevent condensation and sooting. Despite the current bypass setup, which the dealer swears is exactly-correctly-configured, in a 20 minute call for heat on a mildly cool day, I counted 6 interruptions for condensation protection by the Display Energy Manger, which was functioning correctly based on its display of the return water temp, which appeared accurate. The small bypass pipe is hot, the large return pipe is cool, they blend together and yet still crash the boiler temp and cause a condensation-protection shutdown. Either that’s normal or it isn’t, and if it isn’t, why is the dealer telling me there isn’t anything to do to correct it? Could this be one part of why the efficiency is off? Is my boiler momentarily micro-sooting and harming its efficiency?

I want so badly to love my EK, which I researched long and hard before installing, and researched even more now that it doesn’t seem to be meeting expectations. My dealer’s people are extremely nice, but getting this all up and running and balanced correctly doesn’t seem to be a high priority; weeks go by with nothing happening. And I feel like the fluid dynamics and what I would call “master plumber” issues are not their forte. (Like it seemed to be a foreign concept when I mentioned that normally you want to have at least six pipe diameters of straight pipe upstream of the closely-spaced tees in the Hi Mass/Low Mass headers.) And while they now acknowledge the most-obvious mistakes (cross-wired thermostats, cross-piped returns, ProPress connections turning green, no check valves on mixing valve at the DHW tank outlet so a DHW call pulls hot water from the top rather than just cool water from the bottom of the tank, DHW system plumbed from a one-inch trunk cold to a one-inch trunk hot through a one-half-inch pipe which limits flow, no strainer despite being called for in the EK drawings, non-functional DHW recirc, and more), they claim that everything else is fine.

And yet we’re at 22.5 percent efficiency improvement in a shoulder season, where the EK should be at its best.

Is 7 shutdowns in a heat call “normal”? (These have reduced on the coldest days because the water in the zones doesn’t sit idle long enough to cool much.) Could that be part of my problem? Do I need more bypass?

What would “normally” account for this reduced gain in efficiency? I would greatly appreciate the wisdom of the members here, so I can speak intelligently with the dealer.

EBEBRATT-Ed

EK follows this forum so I will leave it for them to respond. They know the equipment much better than I do. Watch here in a few days for a response.

22% efficiency gain is nothing to sneeze at. People have to be careful promising big #s

I agree that 6 interruptions for condensation protection in 20 mi. Does not seem correct to me

109A_5

"I counted 6 interruptions for condensation protection by the Display Energy Manger"

"Is 7 shutdowns in a heat call “normal”?"

Not an EK expert, but I did not find anything in the manual about a boiler shutdown for condensation protection.

Or are you referring to a zone valve closing ?

wjcandee

I'm so sorry if I wasn't clear. What I'm talking about is the halting of the injection by closing the zone valve, which concurrently prevents flow from the return into the primary loop while the boiler reheats. The burner keeps firing of course, so the supply temp will raise and the bypass will still flow, and the zone valve or valves will open when the return water, which then is primarily bypass, reaches 140. When the zone valve opens, new slugs of cool water will mix with the bypass, causing the return water temp to drop again and eventually the zone valves to close again as directed by the display energy manager for condensation protection. What you quoted is a slightly earlier version of the instructions, but basically describes the principle of operation. The ball valve controlling the flow of bypass water through the flat plate exchanger is wide open.

109A_5

Personally I'd want the bypass dynamic and automatic, not a fixed valve. But that would cost more and I don't know if it would help improve the perceived efficiency any.

"What you quoted is a slightly earlier version of the instruction" Then they don't have the current version on their web site.

How do you quantify your DHW usage compared to the neighbor ?

pecmsg

every house is unique. You cannot compare the 2!

Roger

Thank you for your post, @wjcandee , and for everyone's comments.

The first point I'll make is if you have any concerns that you feel are not being addressed to your satisfaction, you should contact us directly at (908) 735-2066 and ask to involve your territory manager. This will clear up many of the questions you posed and allow for a prompt resolution. We should have our territory manager and your dealer talking directly about your concerns.

You high water volume system with cast iron radiators has low mass/high mass piping installed (primary/secondary piping), which is excellent.

Regarding efficiency, give the system a chance to work while properly installed. It sounds like you've ironed out some issues so you should be in good shape after our territory manager reviews your job with the dealer.

Here is some background on energy savings, which may or may not be applicable to your situation (I'll use an oilheat example). When we analyze savings, we usually look for two years of prior history and at least one year afterwards. It's difficult to gauge when oil tanks are sometimes completely filled and sometimes not. Over the course of a year and with the delivery company intentionally filling the tank at the beginning and the end of the year will allow much more accurate estimates. It's also important to realize that we need a good "starting fill" to estimate fuel consumption properly. For example, if the tank is completely filled on June 1, the boiler is installed September 1, and the tank is then completely filled again November 1, there are 3 summer months of usage under the prior boiler, so we can't start estimating until deliveries are made sometime (preferably a year) after then November 1 fill. We then normalize the savings using heating degree day data from a local weather station.

Analyzing a mix of heating and hot water fuel use over a short period of time even with degree day data is not a preferred way to gauge performance. You have an EK2, so you will have a large heating load so this may be even more pronounced.

The primary/secondary (low mass/high mass) zone valve opening and closing is protecting the boiler from condensing. The burner will run without shutting off during these cycles. This does not reduce the overall boiler efficiency, but improves comfort and protects the boiler. Here's why: The circulator on the primary loop (which goes out to the radiators) continues to run with high enough flow that the radiators will typically heat much more evenly. Because the primary loop circulator continues to run, the heat distribution is much more even (as compared to a typical boiler where the heating circulator would turn off when the boiler temperature dropped too much from cold returns; this would "pulse" heat out and causes near radiators to heat rooms more than more distant radiators).

There is usually a ball valve on the return of the injection zone, and throttling this somewhat will reduce the number of zone valve cycles. This is a specific setting for a given primary/secondary loop, and once it's set it does not need to be moved again. Nothing hurts the efficiency or the boiler if this is not done, but if it is your preference, it could be adjusted to reduce injection zone valve cycles. Throttling too much could cause the burner to turn off from a high boiler temperature from too much bypassing water earlier than it would with less throttling.

Best,

Roger

wjcandee

Dear Mr. Marran,

Thank you very much for your prompt and thoughtful response. I appreciate your taking the time to address my questions so clearly.

I believe that the EK equipment itself is operating as designed. My concerns have been about the piping details, given the installation issues that have already been identified. Since EK provides excellent drawings and training, I want to be sure that my system ultimately reflects those standards so it can deliver the performance it’s capable of.

I’m very glad to hear that the territory manager will work directly with the dealer, and I welcome that involvement. My goal is simply to have a first-class installation that lets the system operate at peak efficiency, and I’m confident that with your guidance we can get everything dialed in properly.

I also appreciate your clarification about the normal operation of the injection cycles. If EK is confident that the conditions that are leading to the protection cycling do not harm efficiency or the boiler, that gives me real peace of mind.

I do think I have some good data on usage from measuring the tank every couple of days, and I'm enjoying the savings I am experiencing as well as looking forward to seeing even more savings once this is all resolved.

Thank you again for your responsiveness and support. I’ve admired EK’s design and corporate operating philosophy for years, and I’m looking forward to seeing the system performing exactly as it should.

Best,

William

Roger

Thank you for your kind words, William - I appreciate your comments and thoughtfulness. We're here to help and if you haven't done so already, please reach out or PM me so we can connect you, your dealer, and our territory manager to help review and resolve any concerns you may have.

Best,

Roger