Bypass question

[daffs]

Hi,
About three months ago had a replacement boiler (Worcestershire Bosch Greenstar 24Ri) and hot water tank.
It's an open system.
Twice during the cold snaps last month the boiler wouldn't start without a reset.
One time the system was on and turned itself off, the other it was off and didn't fire up on the timer.
The boilers fitted in an un-heated extension area.
The light on the boiler was flashing (mostly off) both times.
Anyway.... I contacted the installer who suggested I contact WB.
The engineer came round and the only discrepancy he could find was I didn't have a bypass circuit.
I contacted the installer who said I didn't need one as the valve (next to the tank) was a simple paddle and there was always a return path to the boiler.
One radiator is always full on.
That sounded reasonable, but I was piggy in the middle and asked him to discuss it with worcester.

Of course no ones called back so before I follow up on this I thought I'd canvas the expert opinion available here.

Also on other posts I find mention of a drone also associated with by pass circuits.
I also seem to have a very (very) low drone but can't pin on the central heating - doesn't change whether it's on or off & pressing my ear against pipework/boiler/tank.
I can't honestly say it emanates from any of it. It's just "in the air" & to be honest I can't pin this down to when we had the boiler changed, but we haven't always had it.

In summary - do i need a bypass circuit?

Thanks.

 

[gas4you]

Most on here will say that with a 3 port mid position valve you do not need a by-pass.

If you have 2 2 port valves then you do.

I always fit an auto bypass valve to all my systems that have either of the above. This goes back to the early days when the ball in the 3 port could expand and block any flow anywhere.

WB engineer is correct and quoting the energy efficiency regs IMHO.

Auto bypass will not cause any noise as it only opens if it is needed.

 

[bengasman]

Do you need a bypass?
The answer is simple; check your boiler manual. If it says you need a bypass, you do.
Provided you get an automatic bypass and tune it properly, it never hurts to have one.

 

[daffs]

Thanks for the responses.
RTM was a good suggestion where it says "bypass is not necessary on a Y plan system" which is what I have.

So I'll leave well alone and wait for the boiler to fail next time it gets cold I suppose.
Thanks.

 

[gas4you]

Not really the proper result though. You need to know your boiler is fixed and reliable.

Everyone keeps harping on about how good WB service is (myself included) perhaps they are not as good as we all think

Your WB engineer may have worked for Ideal previously