It's 1 a.m.—Do you know where your Obamacare is?
The federal government's health insurance marketplace is—again—shutting down its online application section for several hours early Tuesday morning to address persistent technical problems that have dramatically bogged down the system since it launched last week.
And even as the Department of Health and Human Services on Monday said the work it did during a similar off-hour shutdown over the past weekend "is beginning to show results," particularly in reducing wait times, criticism about its glitchy, slow Healthcare.gov site continued.
"This is not normal maintenance, this is a huge fix," said Bill Curtis, chief scientist of the software quality analysis firm CAST Software.
"You just have a system that is in gross overload right now," said Curtis, whose firm is not involved in the fixes being made to the federal marketplace. "You've got just a constellation of problems here. ... It has all the hallmarks of a project that was in a rush."
One of those hallmarks was a screen that many visitors saw when they went online to HHS' Healthcare.gov site, which asked them to wait and be patient because of the high volume of visitors. That, and similar messages, have been seen by millions of people visiting the federal and state insurance marketplaces since enrollment in Obamacare began Oct. 1.
HHS said that it is not satisfied with the performance of its website, which is handling health insurance enrollment applications for the residents of 36 states that are not running their own Obamacare insurance exchanges.
(Read more: Just 1-in-100 Obamacare applications are clean)
HHS continues to blame its site's problems mainly on the the high volume of visitors—more than 8 million—logging on to the site to check out the prices of insurance being sold there.
"Our work to expand the site's capacity has led to more people successfully applying for and enrolling in affordable health coverage online, with wait times being shortened by approximately 50 percent since Friday," said HHS spokeswoman Joanne Peters. "But we won't stop until the doors to Healthcare.gov are wide open."
To address the overload, the department during the shutdown set for early Tuesday is adding more data servers to the marketplace, moving the "over-stressed" part of its system from virtual machine technology to dedicated hardware, and making changes to software to make the entire system more efficient.
Some of HHS' software improvements appear to already be bearing fruit. On Friday, CNBC.com reported that some insurers were seeing that just 1 in 100 applications that were being passed along to them from Healthcare.gov contained accurate-enough information to enroll a person in coverage without having to ask a person for additional information about themselves.
Several experts told CNBC that that low number of usable applications reflected flaws in software design that had nothing to do with the traffic levels blamed by HHS. But on Monday, an insurance industry source said "that stuff is coming in better ... some of the files are actually pretty clean."
(Read more: Conquering the Obamacare glitches)
"They seem to be more accurate than what they were initially," the source said.
Bobby Koritala, the chief product officer for insurance data integrity firm Infogix, agreed, saying, "We're not hearing the same kind of alarming stuff that we were."
Still, very few people have gone through the application and enrollment process and actually had their applications sent to the insurers they are seeking coverage from. Out of the 7 million people that HHS wants to get enrolled by the end of open enrollment March 31, only several thousand or so are believed to have signed up to date.
Neither HHS nor the states running their own exchanges are releasing enrollment numbers yet. HHS expects to first do so in mid-November.
Koritala said that insurers he's spoken with in recent days have told him that they are getting more enrollments from customers who are contacting the insurance companies directly than from customers who are choosing those insurers' plans from the federal marketplace's options.
David Aponovich, an analyst with Forrester Research, said the clunky websites of the health insurance exchanges could significantly affect the perceptions of Obamacare by the public, which tends to view the health-care reform program negatively overall, and which also has a very low rate of knowledge about the details of the program.
"This is not the best experience," Aponovich said of the Healthcare.gov site. "And it has the chance to impact people's perception of the prices, or then the law, of how they will be taken care of, so I think the government has some work to do to show that this is not an overall sign of how the program will run."
"There's certainly an IT issue here, there's a customer service issue, and there's certainly a big PR issue here," he said.
Avik Roy, a health-care analyst with the conservative Manhattan Institute, said that when the government-run insurance marketplaces launched last week, he didn't think the technical problems would end up having a serious impact on enrollment. But Roy noted continued online problems, and public attention being paid to them, including a "Saturday Night Live" skit, suggest there could be lasting fallout.
"This story has legs with the public in a way that other stories about Obamacare hasn't," Roy said. "I think that could discourage people from signing up."
Roy said that if the technical problems continue, then HHS may decide to extend the open-enrollment beyond six months, past the March 31 deadline. "I'm certain that if these problems last a month, then they'll delay" the close of enrollment Roy said.
HHS on Monday said it was not considering any such extension.
(Read more: Obamacare launches)
And Chini Krishnan, CEO of the Web insurance market GetInsured.com, which will be partnering with the federal marketplace to sell the insurance plans being offered there, said he believes Healthcare.gov's technical problems are fixable, and not unusual for any large-scale technological system launching operations.
"I think these problems will be solvable, and in a few days or weeks it'll be up and running" as originally designed, Krishnan said.
—By CNBC's Dan Mangan. Follow him on Twitter @_DanMangan