Marsal Deck Oven - Heat Issues

Hey all - first time poster, long time lurker here!

We run a couple of pizzerias in New Zealand and are hoping to get some advice/ insights on issues we’re having with one of our ovens. We use Marsal gas deck ovens - one is a MB60 double stack, the other an SD226 double stack. Both have been running for about three years and were purchased new.

Lately the MB60 has been giving us trouble - it hasn’t been hitting the same max temperatures that it used to and heat retention during busy periods has gone downhill. We run it at full throttle (650F) all day. Initially, we’d have to be careful not to burn the bottom of our pies at the start of the day (4 hour heat up time) but now, we couldn’t burn a pie if we tried!

Have had several visits from our gas technician and he is sure everything (thermostat, burner pressure etc) is as it should be, but we still aren’t getting up to the same temps we used to. Burners look like they are burning clean (mainly blue with a little yellow/orange) but I am no expert. Our infared thermometer tops out at 280C so we can’t accurately map the floor temperature of the oven unfortunately.

I did a test bake today - cooked an 18" Margherita in the SD226 and one in the MB6o with the same dough and toppings. The SD226 was done in 5.5minutes with great bottom colour and char- almost too much, the MB60 took 9 minutes and lacked colour and character……this is despite the MB60 being a higher spec’d oven with brick lined roof and walls

Has anyone out there experienced something similar? Any tips on what we should be looking at / trying / troubleshooting? Have been speaking with the supplier to try and figure out but thought it’d be worth posting here as well.

I have attached an ‘up skirt’ photo of each of the pizzas from today

Any input would be seriously appreciated

Thanks in advance

Tommy

Tommy;
Just a wild guess, but I would be highly suspect of the thermostat. From what it sounds like, your oven isn’t getting up to temperature, hence the long bake time, lack of color and inability to keep up during busy periods. I would set out to purchase a new IR thermometer that will read to 350C or better, then you can use it for measuring anything you need to get a temperature on.
Tom Lehmann/The Dough Doctor

Get a grill thermometer and measure the chamber temperature. The thermostat could be “working” as far as your tech is concerned, but that doesn’t mean it’s working right.

These decks are as basic as basic gets. Improper temperature and temperature fluctuations have 100% always been the cause for us over the past 47 years that we have had our pizzerias. The usual culprit for us, due to the bakers pride y600 silly design, is the thermostats capillary tube gets hit over and over and eventually gets a hairline crack in it.

Tommy;
Just a wild guess, but I would be highly suspect of the thermostat. From what it sounds like, your oven isn’t getting up to temperature, hence the long bake time, lack of color and inability to keep up during busy periods. I would set out to purchase a new IR thermometer that will read to 350C or better, then you can use it for measuring anything you need to get a temperature on.
Tom Lehmann/The Dough Doctor

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I’d like to add on to Mr. Lehmanns suggestion of using an IR thermo, and make sure the model you choose has the upper range limit needed. Some are only accurate to a certain upper limit.
I really like the products available from Thermoworks, they’ve got some great combo thermometers, HACCP thermo’s, logging units, etc.
Try to stay away from the lower price combo units, the probe is sort of slow, and the IR capabilities are limited too. I highly suggest one with a laser pointer so you know exactly where you’re reading.
Also, IR units have issues with reflective surfaces such as stainless and glass