I'm new to the Forum, so let me start off by saying "hello" to everyone - this is a great source of advice and am happy to be here. My house was built in 2008 and I chose a Mendota DXV45 in my living room. It's been a so-so performer since new. I'm running propane and the fireplace was converted (supposedly) from NG when installed. I purchased the Mendota because of its heating ability and general excellent quality rating. I saw many video-commercials of Mendota fireplaces and the local store had display items that looked great. Mine has never achieved the look of a woodburning fire - it's always looked more like my gas range! But putting aside the look of the flame for a moment, it's also always been a slow starter. From Day 1 it's started with a "whooph". From the time the unit is turned "on" there's been a lag of 5-7 seconds and then boom, it ignites. When the fireplace was new I had the technicians out twice with no improvement; they said it's pretty normal for these fireplaces and wouldn't hurt anything. The technicians didn't seem too savvy, so I tried another company and paid another chunk of cash to have them clean and address the delayed ignition problem with no better a result. So I put up with it for years, but was always uncomfortable - the fireplace didn't get used much mostly because of the starting problem (my wife won't go near it). Last season the pilot wouldn't light. When I called the techs I was told they were swamped and it would be a month or two before they could schedule an appointment. I'd had enough... I generally don't mess with gas, but time for tools. It took me about 30 seconds to see the problem - the thermocouple was burned through. A little research revealed that a hi-temp thermocouple should have been installed when the unit was converted to LP... it wasn't. I had to remove everything to get the thermocouple out - a very tight fit. I was hardly impressed with Mendota's design; hard to get at things and a flimsy arrangement for the pilot assembly and unfriendly to maintenance. I elected to install a new pilot assembly since I found the flame hood on the pilot was bent and cracked (probably during a ham-fisted installation) and didn't want to have to do the job again if the thermopile needed replacement. I sealed everything up with hi-temp sealant, re-installed the logs per instructions, and fired it up. It worked as it did before... started a little faster, but still a lag and a "whoomph". This season when I started the fireplace I got a bit more than a whoomph, I got a fireball and what I would call an explosion. One thing about Mendotas - the glass can definitely take an overpressure! Here's my question - how can I get rid of this delayed start once and for all? It's definitely not normal and has been there since new. Here's what I can tell you: 1. The pilot, thermocouple, and thermopile are clean, good clean flame (although it hits the thermopile at the base - I've read it should engulf the thermopile or hit it more towards the tip) 2. The thermocouple is operating correctly - voltage is spot on; pilot is stable 3. The thermopile puts out around 330mv which is above the 250mv requirement stated in the manual 4. The logs are installed following the manual to the letter - everything matches the placement photos 5. Nothing is blocking the pilot assembly At this point I'm wondering whether I've been fighting an uphill battle with this fireplace from the start, and whether it was installed, and converted to LP, correctly. I'm also wondering whether I have an issue with the gas valve, or whether the mixture is somehow wrong. I don't have any issue with sooting, but the unit has always produced a pretty meager flame compared the tall, licking flames you see on the videos. When you build a new house it can be frustrating dealing with system installers. I've had to sort out perplexing issues with improperly installed heat pumps, well pump, garage door openers, and a host of other items that required significant rework. Time now to fix this *&$#%(@# fireplace! I appreciate any advice you can provide - thanks in advance!!