Is it worth running 22mm from 20mm mains?

[dilalio]

The cold feed to your combi boiler could also do with a mini shock arrestor.

What boiler is it?

 

[SJRSJR]

The cold feed to your combi boiler could also do with a mini shock arrestor.

What boiler is it?

This is news, have never come across this before. It's an Ideal Atlantic Combi 35W.

So do you fit it as a matter of course and where? The pipe to the boiler comes in under the floor and there's an elbow up to the boiler.

 

[dilalio]

This is news, have never come across this before. It's an Ideal Atlantic Combi 35W.

So do you fit it as a matter of course and where? The pipe to the boiler comes in under the floor and there's an elbow up to the boiler.

Frame 6 of the installation manual...

IMPORTANT. Provision must be made to accommodate the expansion of DHW contained within the appliance. If the DHWinlet contains a back flow prevention device or non-return valve,e.g. a water meter, then a mini expansion vessel should befitted between the device and the boiler in the cold inlet pipe

 

[dilalio]

 

[SJRSJR]

Thanks dilalio

So it says to fit one to the DHW inlet 'if it contains a back flow prevention device or non return valve...' . From what I've searched on, a pressure reducing valve is neither of these?

 

[dilalio]

Thanks dilalio

So it says to fit one to the DHW inlet 'if it contains a back flow prevention device or non return valve...' . From what I've searched on, a pressure reducing valve is neither of these?

But are you on a water meter?
That does, and your stopcock should have backflow prevention too!

 

[SJRSJR]

But are you on a water meter?
That does, and your stopcock should have backflow prevention too!

No, I'm not on a water meter and didn't know that stopcocks had them. I've got a plastic twist one on the MDPE pipe outside and will have a Hep20 ball valve on the inside pipe.

Should water companies advise you to do this when getting a meter? I don't recall this at my previous house, I'm sure I'd have remembered

 

[dilalio]

No, I'm not on a water meter and didn't know that stopcocks had them. I've got a plastic twist one on the MDPE pipe outside and will have a Hep20 ball valve on the inside pipe.

Should water companies advise you to do this when getting a meter? I don't recall this at my previous house, I'm sure I'd have remembered

It's in the manual and benchmark for us Installers.
Hydroblocks can experience a very high pressure when a hot tap is turned off.
Some are very good at pinholing due to the persistent shockwave this causes.

 

[SJRSJR]

Ok thanks, will get one sorted. So should it go after the stopcock and pressure reducing valve and before it tees off, so that it protects everything, not just the boiler?

 

[dilalio]

Ok thanks, will get one sorted. So should it go after the stopcock and pressure reducing valve and before it tees off, so that it protects everything, not just the boiler?

I put one on cold inlet to boiler as this is what is prescribed for Installs.

 

[SJRSJR]

Yes, I've since read it should be as close as possible to the appliance. Since the dishwasher and washing machine are in the same room but on different branches, should there be one on each ? Is there much difference between Flomasta or Sioux Chief arresters?

 

[dilalio]

Yes, I've since read it should be as close as possible to the appliance. Since the dishwasher and washing machine are in the same room but on different branches, should there be one on each ? Is there much difference between Flomasta or Sioux Chief arresters?

If you want the compression tee included and don't want to pay silly delivery price, go to your local independent plumbers merchant and pick one up.

Flomasta or altecnic is fine.
Sioux chef more for commercial kitchen appliances.