? incorrect plumbing

[barnetboy]

Hi,

I've just moved into a house with a 'traditional' HW and CH layout.
The central heating & hot water work fine, but the pipework is not plumbed as I expected.

Firstly, from what I understand, the vent pipe to the feed & expansion tank should come off the flow pipe from the boiler before any valves, pumps, etc. However, my vent pipe appears to split off somewhere in the airing cupboard, after the pump and valves. Is this safe?

Secondly, I also thought that the flow from the boiler should feed the upper pipe of the coil in the hot water cylinder and returns back to the boiler via the lower pipe.
On my hot water cylinder, the flow enters the lower pipe and returns back to the boiler via the upper pipe. Is this incorrect or less efficient?

Assuming my understand is correct and the pipework is incorrect, any advice would be appreciated.

Cheers,

Paul.

 

[doitall]

Can't say about the vent, it would need a photo or sketch.

Plumbing the flow into the bottom tapping is quite common, and there are those that think it's more efficient, and for sure you get more heat/hot water.

One of the unvented cylinder manufacturers have started the practice, and my cylinder has been like it for years.

 

[barnetboy]

Thanks for the reply doitall.

I've sketched the layout of pipework in the kitchen from memory, but cannot recall the layout in the airing cupboard. Is the information in the sketch sufficient?

Thanks in advance,

Paul.

View media item 4570

 

[shambolic]

It looks like your cold feed is coming in at the return and the open vent will be of the cyl This will cause problems with air sludge etc due to the neutral point of the system being in the wrong place.
One way round it is to use your cold feed as a combined feed and expansion (one pipe provided its over 22mm) and bring this into the flow and cut off the pipe in airing cupboard altogether or fit a manual point where you remove pipe.

 

[doitall]

Forget shambolic's post he obviously hasn't read the question

As the drawing is so you will need to update it to be able to comment.

There's no by-pass shown.

And as you suspect the cold feed and vent would be in the wrong place, although not shown in the sketch.


What boiler make and model is it.

 

[shambolic]

 

[barnetboy]

Gents,

Thanks for all your help so far. I am away for a long weekend, hence the sketch from memory, but can provide a more detailed sketch on Tuesday when I return.

Doitall, the boiler is a Halstead Balmoral 55 but I am planning to replace it at some point in the future, as it is well past its use by date.

Thanks again,

Paul.

 

[barnetboy]

Doitall & Shambolic, apologies for the delayed reply but work occasionally gets in the way.

I've attached a new sketch showing the pipe layout in the kitchen and airing cupboard but, unfortunately, I lose track of the pipe work as it enters the loft. All pipe work is 22mm, except where the return pipe exits the cylinder, which is 28mm.
I spoke with the previous owner who told me that he had previous problems with the CH, which was cured by Teeing the flow pipe into the return pipe, but unfortunately, he cannot remember what the exact problem was. Shambolic, is this what you mentioned in your first post?

I plan to change my 2 ancient 2 port valves for a single 3 port valve and position both the pump and valve in the airing cupboard, as they are currently on a wall in the kitchen.

I am assuming that the vent pipe over the F&E tank is the same pipe as the return pipe in the airing cupboard. Is there a test to prove this?
Many thanks in advance for your help.

Paul.

Untitled

• barnetboy
• 19 Sep 2008
• 1

 

[doitall]

Interesting design or not as the case is.

Where to start, other than rip the lot out and re-pipe.

From a safety point, I would class the boiler as ID (immediately dangerous )

The vent is blocked by two valves and a pump, in a fault condition the boiler is in serious risk of jumping of the wall.

The system has no by-pass valve, between the pump and MV's.

Make and model of boiler please.

 

[barnetboy]

Hi Doitall,

The boiler's a Halstead Balmoral 55.

Paul.

 

[doitall]

Hi Doitall,

The boiler's a Halstead Balmoral 55.

Paul.

Wished I hadn't asked now.

Never heard of it some research is called for.

 

[doitall]

Done the research

The cold feed and vent must be between the boiler and the pump, as I would have expected.

You also need a by-pass valve

 

[barnetboy]

Done the research

The cold feed and vent must be between the boiler and the pump, as I would have expected.

You also need a by-pass valve

doitall,

Thanks for your prompt replys.

I am going to plan B, which is to replumb the pipes correctly and, when funds allow, I shall have the boiler replaced.
I will move the pump into the airing cupboard and replace the two 2 port valves with a single 3 port valve, also located in the airing cupboard.
I am more than happy to plumb these in myself.

With regards to the above, does this mean that both the cold feed and vent should come off the flow pipe, before the pump? I was always under the impression that the cold feed should be connected to the boiler return pipe and the vent pipe connected to the flow pipe.
Also, for the bypass, is it ok just to plumb in a half open gate valve or should there be something a bit more high tech?

Thanks yet again.

Paul.

 

[doitall]

Should be boiler, vent, cold feed within 150mm, pump, three port valve.

With the 3port valve you don't need a by-pass because one port is always open.

You will need an air vent on the primary pipes to the cylinder.

 

[barnetboy]

Thanks,

All beginning to make sense.
Can I ask you to clarify the last point about the air vent on the primary pipes to the cylinder.

Is this in addition to the vent pipe? If so, is it a case of extending another pipe to vent over the F&E tank or is there something more compact available that can be fitted.

Here's a nice cold one for your Friday afternoon!

Untitled

• barnetboy
• 19 Sep 2008
• 1

Cheers again.
Paul.