how to drain & refill Ferroli Optima 901 combi boiler

5 Jan 2006
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United Kingdom
Hi hope someone can help

we have just bought a house that has a ferroli optima 901 combi boiler which works perfectly.

However, one of the thermostatic radiator valves is broken and needs replacing and I need to drain the system, replace valve and refil / re pressurise system.

I have all of boiler instructions but this is our first combi and I dont want to break it (ie no heating in winter) (the broken valve is set to hot)

please can anyone help

thanks in advance

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Depending on the age and brand of TRV, you don't necessarily need to drain the system at all.

Can you supply more details, viz:

1. What is the make and model of the TRV?
If you don't know then please just describe it, or post an image

2. Which part of the TRV is broken?
Hi, thanks for replying to my post

it is a drayton TRV that has a metal turning bit at top with the numbers on and a beige plastic cowling that should be attached to the metal pipe fitting / coupling that attaches to the radiator / water pipe.

however the plastic / metal turning bit has been broken off by previous house owners. there is also a loose plastic pin that is forced up / down depending on what temperature you choose.

so the valve is stuck on hot with no way to turn it down.

is this any help?

the boiler was fitted in 1997, not sure if valves are same age.
i am not sure how to post a photo

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I suspected as much. This is now easy, and you don't have to do any plumbing whatsoever :D

You can buy the TRV head on its own, and simply screw it on. If the existing head is broken then you might have to undo the knurled retaining but, but wait until you get the new head before you 'fiddle'.

BTW, do not, under any circumstances, pull the exposed pin, and don't do anything that risks bending it.

Any word of advice - few plumbers merchants stock the heads, because it's often more expensive than the valve including the head. I recommend that you buy a complete valve, then you'll have a spare that you can use if it turns out that this one is faulty, or if one jams up in the future.

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