# R58 OPV drip plus a couple of other questions regarding temp and pressure



## dan1502

There is a drip coming out of the exit above the drip try which I understand must be coming from the safety OPV. Is this normal and if not, what should I do to resolve it?

Also, I'm a bit rusty on this but what pressure should the pump be set to if measuring with a gauge attached to a portafilter?

Then on to temperature. I realise part of the point of the PID is to be able to adjust the temperature but what is a good default? Mine is currently at 107 degrees. I also feel I need to learn more about when to/the effect on taste of adjusting temperature but prefer to leave it as is for now whilst I familiarise myself with the effect of adjusting other variables with regards extraction first.

Thanks.


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## Mrboots2u

What the pid offset ? 93 after offset isn't a bad middle of the road temp to start at


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## dan1502

Thanks, that would be about 106 degrees.


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## hotmetal

I've got an R58. I also leave my PID at 107 which equates to 94 by all accounts. Like you, I've tended to leave it there. There are enough other variables to worry about! Although I won't go as far as to say that the coffee couldn't be improved with a small temperature tweak, I've never had a shot that made me think "must change temp cos this is over/under". Therefore I've found that 107 seems a good default - I'd only change it if I found a certain bean needed a change.

Don't worry about the few drips that come out of the chrome disc above the drip tray. That's not the OPV or safety valve as such - it's quite normal, as the boiler starts to heat up, for a few drops to come out of there as the cold water in the full boiler starts to expand. That is what that thing is for so do not fear. It should stop after a few minutes (when the water has expanded as much as it's going to).

Pressure wise I've just accepted the reading on the manometer on the front panel as being accurate enough. The rotary pump can be adjusted from underneath the machine but mine shows a solid 9-and-a-bit after the initial slow ramp-up.

I reckon worry less drink more! ?


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## Glenn

As hotmetal says - it's normal unless it starts to release a lot of water (in which case it is stuck partially open)

How old is the machine and how much is coming out?

They can be replaced quite cheaply (c. £45 for my machine - an Alex Duetto) if they do fail at any point.

In the last week mine started playing up so have dropped the machine off for a full strip and service as it was due it (hence I know the cost)


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## dan1502

It's a drip every two or three seconds I'd guess. I'll look closer next time and see whether or not it stops after warm up.

Being my first rotary pump machine I watched the WLL video of the internals as I wasn't sure whether it would have an OPV but it seems it does but just to act as a safety valve. I do the usual thing of letting the vacuum out of the boiler before switch on to avoid the knocking.

It's just over two years old. I'm quite happy about changing things if needs be but I suspect it's nothing to be concerned about.

I'll be changing the group head as some point so shall probably do a descale at that point but I believe it's never been used with hard water.


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## hotmetal

That drip sounds perfectly normal but it only happens for a minute or two. If water was squirting out everywhere or if it doesn't stop when the boiler is up to temp then it would need replacing but if it stops after a couple of mins that's normal.


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## dan1502

Ok, thanks, I'll check tomorrow.


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## MediumRoastSteam

dan1502 said:


> Ok, thanks, I'll check tomorrow.


My Profitec 700 does the same. Basically it will drip as the steam boiler goes over 100C and as it reaches temp it will stop. It will also drip now and again, but mine never drips when I am making a shot or back flushing for example, which eliminates that this is the relief of the OPV. On machines equipped with rotary pumps, the OPV is a safety device, is should never really open as it is set to open at a higher pressure (say, 12 bar) than the pressure at the pump, usually set to 9 bar.

I believe this is the exit of the over pressure valve for the steam boiler and the OPV.


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