Changing and teeing into Flow & return pipe

[littlepigeon]

Hi all,

Looking for a bit of help with moving some pipes.

We are having some work done and i need to move a few pipes around to tidy things up. I called a plumber in to look at the work and have been quoted an astronomical amount when compared to what the rest of the work is costing. I think its down to it being a bit messy and crawling around in roof space being part of the job. I have no issue in doing this and feel pretty confident in pipe work as long as its not soldering and tidy on show stuff (this isnt) so am taking on the task myself. Fingers crossed

I am looking at moving our central heating return pipe, which tees into the return pipe coming from the loft (cylinder location) near our boiler, into the roof space above our kitchen and teeing back into the main return from the loft further back which is also in the roof space. This is going to take a bit of arsing about to run the pipe round a few obstructions.

Is there such thing as too many 90 degree joints or too long a pipe run?

Also I'm going to use plastic pipe for the majority of the work but i understand near the boiler this has to be copper. How much of the run from the boiler has to be copper before i can change to plastic?

Cheers all
Gav

 

[CBF]

normally the first meter off or onto the boiler must be copper, don't forget the cylinder return must be the last connection before the boiler if it's not your rads could start to heat up when only the water is on.

 

[littlepigeon]

don't forget the cylinder return must be the last connection before the boiler if it's not your rads could start to heat up when only the water is on.

Really? Why would that happen? I'm sure its not like that now as the return coming from the central heating tees into the return coming from the cylinder in the loft to the boiler.

I'm pretty sure my rads don't heat up when the stat is off. I,ve never noticed it anyway.

I think i may be misunderstanding you though as thinking about that where else would i run the central heating return if it couldnt tee into the return coming from the cylinder? There is only one connection for the return pipe so they have to join somewhere between the cylinder and the boiler...... don't they?


Many thanks for your response

 

[littlepigeon]

think mine may be a little like version1 in this but with only one rad circuit.....

 

[doitall]

Version 2 or 3 is ok, but what is the X designating

 

[CBF]

2 or 3 are fine, if it's done like 1 then when the hotwater is on you could get reverse circulation in the rads as the return water could go up the heating return before it goes back to the boiler, cylinder ret connection should always be the last connection before the boiler

 

[littlepigeon]

Version 2 or 3 is ok, but what is the X designating

No idea i just found that on another forum bu searching for more info. Pretty sure mine is setup at present like version 1 though. What problems would that cause?

Cheers

 

[CBF]

I've just told you

 

[doitall]

I've just told you

But that was before the question.

 

[CBF]

I've just told you

But that was before the question.

now thats what you call good service

 

[littlepigeon]

Sorry CBF completely missed your post.

I'll have to look into it some more as im pretty sure this is how its set up at the mo.

Hi Ho Hi Ho, back up the loft i go!

Whilst i'm on actually i may aswell ask about my pump position....

If my pump is directly after the boiler on the flow and before the vent and cold feed, what could this do to my system? I keep reading things to say this is wrong to but i cant find the problems this may cause.

many many thanks

Gav

 

[Hugh Jaleak]

If pump is situated before vent and cold feed, it is not only putting a restriction in the path of the open vent between the boiler and the F&E cistern, (extremely dangerous!), but will also result in the pump dumping the boiler output straight into the F&E cistern and NOT around the system. Pump will probably put water into the F&E faster than the cold feed can put it back into the system, so you'll have extremely hot water pouring out the overflow, and a system that is being slowly drained, with the possibility the boiler will eventually be starved of water and possibly explode like a bomb.....

Should be a clear upward path from boiler to up and over F&E cistern. At a suitable point a connection is taken off, the cold feed coupled in within 150mm then the pump fitted!

 

[littlepigeon]

If pump is situated before vent and cold feed, it is not only putting a restriction in the path of the open vent between the boiler and the F&E cistern, (extremely dangerous!), but will also result in the pump dumping the boiler output straight into the F&E cistern and NOT around the system. Pump will probably put water into the F&E faster than the cold feed can put it back into the system, so you'll have extremely hot water pouring out the overflow, and a system that is being slowly drained, with the possibility the boiler will eventually be starved of water and possibly explode like a bomb.....

Should be a clear upward path from boiler to up and over F&E cistern. At a suitable point a connection is taken off, the cold feed coupled in within 150mm then the pump fitted!

Oh dear... Its been like this since we moved in almost 3 years ago. There was a flood in the house just before we moved in and teh old boiler was replaced with a new a rated alpha boiler. We had to get them to come back and redo the stat and programmer setup as they had made a proper hash of that so maybe it was them that installed the new pump in this location.

The pump is miles away from the cylinder and vent etc as its right by the boiler which is at the back of the house downstairs in an out building, where as the cylinder and valves etc are all in the loft.

Could this wrong setup be the cause of lots of air in the system also?

I don't think its forcing water back up into the f&e, at what point would i see this if its happening? I've never noticed it in my time trying to work out how the system is setup.

If i was to relocate the pump into the loft where everything else is, what is it that fires the pump, the boiler or something on the control panel in the loft? I ask as, if its the boiler i guess that would mean some extra wiring all the way from the boiler to the loft?

Many thanks for your help.

Gav

 

[doitall]

If there isn't a problem don't fix it.

The plumber should know what he's doing, otherwise get one that does.

 

[littlepigeon]

If there isn't a problem don't fix it.

The plumber should know what he's doing, otherwise get one that does.

Little bit worried about the fact i'm being told my boiler could explode though

I cant be mistaken about the setup as the pump is right next to the boiler on the flow pipe. Everything else is in the loft to which only a 22mm flow & return pipe runs, so its definitely before the vent and cold feed.