STARLOG Trouble Bubble Update:
Well it's been quite a week in the Tundra Dome and I'm quite happy to report that my marriage has survived
SwampHubby has been super easy going with the great gobs o cash I've consumed on my quest for yearround hot water.
So after buying a new air warmer the week prior due to my not thinking through low flow on my vsp, last Sunday night brought us the heater flame rollout condition that for some reason stymied 3 different pool techs and hvac guys.
Of course, if I weren't running in winter, this would not have been the cliff-hanger it was. For posterity, it should be said that if you plan to run a dome in northern winter climes, learn a lot about heaters first because you'll be on the clock when a crisis arises
Might be worth owning a manometer.
I may reserve a complete report until I talk to Hayward again to do some analysis but here's the short strokes and a pic that ultimately tells some kind of story.
By way of background, heater is in a heated pool house with a un-powered draft stack that connects to 7" type b flue that runs a good 29' through 2 stories. The heater is an 18-mo old Raypak 266k btu Cupronickle exchanger running off a 1" gas line on a 400k btu service.
My life is governed by the law of unintended consequences, so I'm pretty sure this developing story does not reflect on Raypak in any way, just so you know.
- Monday I begged to get regular heater pool tech out...skeleton staff and booked up so they suggested having hvac guy out
- Said hvac guy came, changed the sensor, tested gas which was 3.96 (in other words, perfect) and then left saying his co didn't want him taking apart the heater. I wondered what the heck I'd just paid for, since the flame rollout sensor is merely a safety fuse. Heck I could have changed that part myself or jumpered it. The point was to correct the CONDITION causing the flame rollout. Tip: never let someone leave the property until you're satisfied that the repair is logical
- So 20 min after hvac guy leaves, new sensor blows and heater remains down
- Next pool hvac tech comes later that afternoon, pulls out burner and cleans it, says they think the exchanger looks fine and since the company cleaned it 2 mos. ago, doesn't do this. We note condensation on heater floor. tech is convinced it cant be a leaking exchanger. Puts in a new switch and leaves. Tip: Never let a tech leave the property if there is an unexplained phenomenon that you know should not exist
- 5 hours later, flame rolls out and blows switch. At this point we can rule out odds of ad hoc backdraft.
- I jumper the switch to observe burner. Something is clearly wrong as to me it looks like its burning too dirty. I do match test to see if there's a good draft on flu. No obstruction to makeup air vents. Etc. Calculate 1 square inch oer btu, check. Get it into my head that a powered vent might help. By morning, I've sent urgent message to pool guy, who stops by on route to another job. I beg him to clean the exchanger. He's sure that isn't it but thinks a powered vent will work, gives me a different hvac guy's number.
About six calls later, there is still no hvac co in town who can come for a week or two, by which time dome land would be dead unless I blow out the lines. I've convinced local wholesaler to overnight the powered vent hood that at retail costs almost as much as the heater did, not to mention having to swap out 20+ feet of flue to 4" vent...
-By this time, I have a direct line to Raypak guy via the pool co. He's convinced the exchanger HAS to be sooted and blocking/condensing combustion. He gives me name of another authorized tech - thank ye gods because the next one dug deeper.
- New tech comes out and goes to work. Pulls out the heat exchanger, which is a hot mess. Pinhole leaks all over the place. This guys theory is that drips from pinhole leaks may have caused incorrect combustion and sooting, which exacerbated corrosion due to condensate. This pretty much happened somewhere between Sept 11 when it was cleaned for phosphate scale and the rollout event on Dec. 17. He had checked my flue and found no obstruction or sooting that suggested any drafting problems, though we may expand out intake vents propholaptically.
- Another overnight shipping charge later, new exchanger is in, pool is heating, and so far so good. Fingers cross as temps are to drop right when were headed to Canada for Xmas.
Possible and as-yet undetermined lessons:
1. Phosphate scale may indeed be corrosive as Matt dug up in a research paper I now need to locate and read more thoroughly
Next week, I'm going to see if Raypak will analyse it after my endoscope comes in and I take picture. This is not for warranty purposes as online warranty is only 1 year. This is for my own understanding.
2. When you look at pic from sept 11 cleaning to removal, the speed of degradation is profound. Have a hunch that cleaning was a mistake insofar as it was also improperly executed. Won't get into all that now as there's nothing to be done about it, but have learned a few things along the way.
All I want for Xmas is to swim
Hi ho.
Sept 11 Heat Exchanger
Dec 21 Heat Exchanger
I suggest lighting smudge pots around the property. The smoldering diesel flame will produce a nice, dense cloud of particulates and sulfurous compounds. The blanket of smog will keep everything nice and warm 
