Hi,
Got an the Expobar Office Control a few weeks ago, and I have been learning how to use it

I have added the thermosyphon restrictor (got it from WLL)
Installing thermosyphon restrictor on expobar office pulser

I also have added Eric's adapter, along with a type K TC, connected to a cheap meter for now. I eventually plan to build a TC4 + Arduino + LCD, all mounted under the machine, to use to read temps.

Idle temp this morning was 212, after maybe a 1 hour warmup.

I had expected/hoped for short flush times with the restrictor.

To get to 185 at the grouphead, I need to flush for around 30 secs, and about 10 ozs.
BTW, I did calibrate my TC/meter. Based on the barametric pressure reading nearby at the time (29.99), I figured I was right at 212 boiling temp, and my meter read 204 when placed in a pot of boiling water/steam, so I correct by 8f.

I have also adjusted my pressurestat down. Last time I checked, it was peaking a 1 bar, but I have adjusted it lower since, I am probably less then 0.9 bar now. I have to hook up a hose/meter to the steam arm to check it, and I have been too lazy to do it lately. I don't steam much, and it steams fast enough right now, so I wasn't that worried about the absolute pressure.

Just wondering if anybody had any ideas why my flush is still so long, or what else I could do to help reduce it?

Otherwise, I just ordered a float valve. I don't think the long flushes would bother me as much if I didn't have to fill up my tank every couple of days.

Randy

Tomorrow I will time my Vetrano to 185. I suspect my time will be similar to yours.

I use a flush-and-go technique, only flushing to about 201 or so, which works well for me.

sweaner wrote:Tomorrow I will time my Vetrano to 185. I suspect my time will be similar to yours.

I use a flush-and-go technique, only flushing to about 201 or so, which works well for me.

Thanks for checking.

So, you flush to 201, then pull the shot?
When I flush, as soon as I stop, the temp rebounds right away by 4-5 degrees, and then it starts a slower climb back after that.

Randy

The flow restrictor will lower the idle temperature of the group but not the heat exchanger. You still have to flush the super heated water out of the heat exchanger. The only thing you can do about that is lower the pressurestat. Curious why you are flushing down so low, that is darn cool. Some machines work best with a flush and rebound while others do better with a flush and go. You may want to flush to just below your desired temp then pull the shot immediately and see what your temperature does. That will reduce your flush by probably 10 seconds.

Dave, I think he is doing the flush-and-wait method, letting it rebound. That always takes too long for me.

My results:

210.5 ---> 185, 28 seconds, 8 oz. Quite similar to your machine.

Yes, I was doing a flush and wait.

I experimented some with not flushing as much, for more of a "flush and go" , but it doesn't seem to change the flush volumes that much.

I think one issue may be that I am turning the machine (on a timer) on too early, and it is heating up the water reservior, so my cold water isn't as cold, making for a longer flush.
I will play with this some over the weekend.

Randy

Randy -

Calibrate your thermocouple/meter combo in a "pot of steam" - do not let the thermocouple get in the water - convection currents will throw it for a loop. Keep the meter as far from the pot as is possible - meters work best at room temperature although most have correction thermistors to allow for ambient temp swings. I would "say" that with a 1.75 inch thermocouple, there should be essentially zilch showing at the adaptor where the wiring exits.

Measuring PEAK boiler pressure accurately can be a PITA. In any event, lower the boiler pressure until steaming becomes uncomfortable.

Eric
When I calibrated my setup, I put the tc in the water, and got a max temp of 202, then I put it in the steam, right above the water with a lid on the pot, and got 204 max temp.
After I build my arduino setup, I will calibrate the tc again.

I pulled two straight shots this morning, a SO Kenyan that I had roasted a week ago

Warm up machine for about 40 mins

First shot
Group head at 213 start
Flush to 200, a 7 oz flush
Pull shot at 205

Waited about 15 mins

Group head at 212 start
Flush to 195, 8 oz flush
Pull at 200

I thought the first shot was better.

So, maybe I am going to have to live with a 7/8 oz flush.

I was pulling a third shot for a cap, and ran out of water
Plumbing in is looking better and better.

Randy

One last update

I think I have settled into a routine

Warm up for 45-60 mins.

Flush to 205, about 6 oz

Lock in PF, and pull shot at 205 a few secs after end of flush

Seems to work fine, and is pretty consistent.

Thanks for all advice given

Randy