Hot water cylinder install advice

[booke23]

I am just about to replace my ageing indirect open vent hot water cylinder.

The flow for the indirect coil on the new tank is quite a bit higher than on the old tank. The current set up has the 3 way valve at exactly the same level as the flow on the old tank........if I install the new tank with a modified pipe from the 3 way valve, I'll have created a 'loop' that will I guess need a vent to prevent airlocks.

Just wondering what the proper way to deal with this is......should I modify the position of the 3 way valve making it the same level as the flow on the new tank, or is is acceptable to just run a pipe upward and fit a vent at the top, where it goes into the flow?

 

[cr0ft]

I would adjust the position of the mid-position valve if it was me. Difficult to tell without seeing a photo of the airing cupboard to be honest. Is it possible to drop the mid position valve easily?

 

[booke23]

It's a pretty big airing cupboard with loads of room around the tank, so it would be fairly easy to move the valve up to be level with the new indirect flow. But of course it is extra time/labour compared to just putting on a new pipe and vent.

Just wondering what a pro would do, but as you say I suppose it very much depends on the circumstances.

 

[cr0ft]

I would design the system to need as few air vents as possible. So that would mean me moving the valve up/down as required to remove the need for an air vent as opposed to fitting one. That's what my company would do but there may be 2 or 3 other plumbing professionals who have different answers!

 

[lame plumber]

I would fit an s plan, so much better

 

[bigads28]

I'd just replace the pipe from the existing 3-port. Most of the time I also fit a manual bleed point too from a tee on the cylinder flow.

 

[brum]

Is it not common practice to fit auto air vent on cylinder flow (at cylinder on a 15mm rising pipe just at connection to cylinder) have always done this regardless of s or y plan,I have never installed a y plan system always s plan way I was taught..brum

 

[kay-jay]

as you have a 3 port valve your system will be fully pumped which means the water passing through the coil is not relying on gravity circulation. the upshot of this is you can just repipe from the valve and add an airvent

 

[Radioman]

Booke23 you may not be aware of this but if you are not what's considered a "competent person" ie benchmarked or time served tradesman you must inform Building Controls you are replacing the cylinder and are not registered.

Quote from gov. Net

When installing or replacing a hot water cylinder within a vented hot water storage system (i.e. a system fed from an open-ended pipe for venting). The requirements are for the installation to be energy efficient. If you employ an installer registered with the Institute of Plumbing for a vented system, you will not need to involve a Building Control Service.
For either type of system your installer should leave you with a completed installation record and commissioning certificate such as the one produced by the BENCHMARK scheme. Some manufacturers attach BENCHMARK certificates to cylinders ready for installers to complete.

We had one recently that was installed by the homeowner but he had not informed building controls. He Got fined and had to pay for controls to sign off. This was picked up by home insurer who was dealing with an unrelated claim.

 

[stevetheplumber]

i agree no need to move the 3 port you almost always need a air vent in the cupboard no matter how its piped

 

[Dotty]

i agree no need to move the 3 port you almost always need a air vent in the cupboard no matter how its piped

I agree, but not auto.

 

[AWheating]

yep auto by pumps, manuals elsewhere.

 

[booke23]

Thanks for all the advice guys, much appreciated.

Radioman, I've been around the block a few times with plumbing jobs around the house's I've owned over the years, but I'm not time served and not 'competent' as far as any regulations are concerned. I must admit I was not aware of the requirement to get building control involved with the replacement of a vented cylinder.....I thought it was only needed for an un-vented installation. I'll bear this in mind.

I'll see how it looks when I get the old tank out. I am not a big fan of Auto vents unless there is absolutely no other option, so I would definitely be fitting a manual vent if that's the road I go down.

Thanks again guys.

 

[brum]

yep auto by pumps, manuals elsewhere.

Why is this fitted autos everywhere since they became available did not realize there was any reason not to.
What is the downfalls of fitting an auto over a manual please enlighten me..brum

 

[brum]

No need to done it myself should have read thread properly open vent system.Have been working on sealed systems longer than I can remember..brum

 

[PhoenixServices]

Brum the auto air vents crude up and leak if not turned off after use. I now fit a lever valve under any auto air vents I put in.