Re-Pitched WLP 002 Slurry - Not Starting - Should I be Concerned?

I brewed Jamil's ESB two days ago with some changes on the hops.

6 gallons, 5.5 gallons into the fermenter.

12# Maris Otter
0.50 Crystal 20
0.25 Crystal 120
2 oz Challenger (60 min)
1 oz Fuggle (0 min)

Mashed at 152 for 60 minutes.

OG: 1.055 (Jamil's recipe estimate is 1.056)

I pitched 160 ml (used Mr. Malty pitching rate calculator adjusting for harvest time) of harvested WLP 002 yeast that had been in my fridge for 1.5 weeks. I usually do a starter to wake the yeast up a bit, but this time I passed because of timing.

I brought it up to ambient temperature and then pitched to 67 F wort. The carboy has been in my fermentation chamber at 66 F for 2 days now and no signs of activity. I am aware that fermentation could be started, but this is the first batch that I have not seen any visible signs (even with this yeast).

I have more yeast I can pitch. Should I test my patience a little bit more, or dive right into pitching more?

Thanks for all the help!

What was the OG of the beer you pulled the slurry from?

I recently repitched from slurry and didn't have time to make a starter. It took about a day and a half to start, but then it took off like crazy.

Take a gravity reading, and if it hasn't changed by tomorrow, I'd pitch some dry yeast.

Thanks Turkey. The OG of the beer I pulled from was smaller, about 1.040. Mainly because I had terrible efficiency and wasn't patient to rinse all the sugars.

I have a little action in the carboy now so I think I'll just give it a go and let the yeast do their thing - as slow and steady as it might be.

I'd give it another day or two then take a gravity reading to see where it's at.

Oh yeah, if you pulled from 1.040, that's perfect. I was just asking because the first time I tried to clean/reuse yeast, it was from 1.080. Nowadays I never harvest from anything over 1.070.

If you've started to see some activity, just RDWHAHB. It'll be fine.