# Original L1, Mains feed: Understanding the mechanics.



## grumpydaddy (Oct 20, 2014)

Having used this tanked since I got it I can now more easily switch it to mains feed.

Is there a thread on here that I missed that discusses the mechanics of the new flow?

I get that the water pressure does the same job the pump did before but if said mains pressure is say 2.5 bar and high flow, am I going to be seeing the boiler relief valve actuating more?

I gather that unlike the P I won't have mains pressure pre-infusion

Yeah I know it sounds like a dumb question but I want to get my head around just what is happening... I just want to understand.


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## 4085 (Nov 23, 2012)

Basically, you need a limiter on the connection valve. I cannot remember the numbers but I am sure 2 bar is minimum and 3.5 maximum, hence the need to limit it


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## Rhys (Dec 21, 2014)

I had to buy a pressure regulator for my plumbed in machine, and are readily available from Screwfix. This one comes with reducing bushes to take 15mm pipe and has a gauge. It says it's already set to 3 bar (which is roughly what you want for line pressure). I've no idea if Londiniums have pressure regulators built in (but I wouldn't think so..)

My mains pressure is about 4.5 bar. The valves are under £30 iirc


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