Dear All,

I have had a new boiler fitted last year (Vaillant TurboMAX 828E), and
with that a new Bathroom & Kitchen. Since the new items there's been a
'water hammer' problem that has been around, which has now caused me
to act!

I've got 2 ideas....1) Fit a Shock Arrestor or 2) Fit a PRV (Pressure
Reducing Valve). The mains pressure in the sealed system seems quite
high, and I'm guessing that I need to either reduce it (fit a PRV) or
fit the 'arrestor(s)'.

If I fit the 'arrestor' do I really need one for each tap where the
cold water is? Or can I fit it in a place where all taps/showers will
benefit? Bearing in mind that I cannot get access to the pipes for the
shower (concealed behind tiles into the wall), bathroom basin
(concealed behind tiles into wall with a non-pedestal type basin), the
only access to cold water is at the boiler and kitchen sink.

If I fit the PRV, I have no idea where to fit this, and help here
would be greatly appreciated.

Thanks in advance

Mika

The mains pressure in the sealed system seems quite high, and I'm
guessing that I need to either reduce it (fit a PRV) or
fit the 'arrestor(s)'.

The sealed system has nothing to do with it. The pressure is set by opening
the valve until the pressure is as required. Whilst the US happily leave
theirs connected to the mains via a pressure reducing valve, us UK types are
sensibly precluded from doing so.

However, assuming you have a water hammer part in your water supply section
(hot or cold) rather than the primary heating circuit, then indeed, both a
PRV and a shock arrestor can help. However, I would measure the static
pressure and only fit a PRV if the pressure is above around 3 or 4 bar.
Otherwise, shock arrestors it is (or even as well, in the case of a PRV).

You want to avoid using a PRV if the pressure is lower, as it may reduce the
flow rate.

If I fit the 'arrestor' do I really need one for each tap where the
cold water is? Or can I fit it in a place where all taps/showers will
benefit?

The closer to the tap they are, the more effective they will be. You may
find that you get away with one in the bathroom covering all outlets.
However, if you have a serious problem, you may need one per fitting, fitted
closely.

As for fitting one in the kitchen to cover the bathroom, you could give it a
go, but you might be disappointed (or might not).

If I fit the PRV, I have no idea where to fit this, and help here
would be greatly appreciated.

Fit it in the rising mains, preferably after the garden tap (and maybe
kitchen tap), but before any bathrooms, laundry appliances and water heating
appliances (i.e. combi boilers/heat banks).

Christian.

Mika wrote:
Dear All,

I have had a new boiler fitted last year (Vaillant TurboMAX 828E),
and
with that a new Bathroom & Kitchen. Since the new items there's been
a
'water hammer' problem that has been around, which has now caused me
to act!


ways to ersuce the problem:

replace rubber washers in ballcock/taps, this is the main cause of
trouble.
turn down flow rate slightly on any noisy ballcock
clamp pipes securely to wall where not already
fit service valves and turn them down from full just slightly. Put
where the vibration is greatest in the pipe.
If the pipes are unexposed, mechanically absorbent lagging often stops
it, eg carpet offcuts or lagging.

ewe con teal eye dont yous a spall chequer car NT yew?


NT