flow and return on regular boiler, how to tell

[diydad888]

Hi,
I am replacing a Baxi wm38 3 rs regular gas boiler with a new Worcester greenstar 24 ri, I have disconnected the old Baxi but I was unsure which was the flow pipe and return pipe. one pipe did have a drain at the lowest poin, would that be the return pipe?
The worcester has ports named flow and return but the Baxi had no indication.
Thanks

 

[HERTS P&D]

Which one got hot first?

Who's doing the gas work??????????

Andy

 

[45yearsagasman]

As you looked at the old boiler the flow was the LH pipe. If you go toBaxi Parts Arena all will be revealed.

 

[diydad888]

Thanks for the parts arena info, I may be forced to do this job myself as only one gas engineer turned up ( I was out buying materials) out of 20 calls I placed locally.
I don't think anyone wants to do a simple boiler replacement..and I already got the new boiler...I guess no one sees enough profit to be bothered.
It is a simple regular boiler exchange, old boiler removed already, pipework tidied up and blanked off.

 

[Agile]

Generally customers who buy the boiler themselves are seen to be cheapskates and not viewed as the ideal customer.

My charges are completely transparent and I would be charging about £740 to install the boiler that you have bought.

Is that about what you expected?

Tony

 

[Agile]

Your current boiler is 11.14 kW.

Why are you rep[lacing it with a 24 kW boiler?

Do you think the more powerful the boiler the better?

What is the calculated heat loss of your house?

Tony Glazier

 

[xr4x4]

Doesn't matter what's flow and return on the pipe work, it will work ether way.

Only poss problem will be trvs that only work one way.

 

[diydad888]

I have a 3 bed semi with one bathroom but now adding few more rads and may put new shower room in later. I was on the worcester website and it seems best according to their online calc ( I know is just basic guide)
The Baxi was never great at putting out enough really hot water for a bath, having to run it on max for a couple of hrs, so I always thought it was under spec....have i over spec'd too much ?

 

[Tibbot]

Doesn't matter what's flow and return on the pipe work, it will work ether way.

Only poss problem will be trvs that only work one way.

You what?

 

[cantaloup63]

Out of idle interest op, how do you intend to check for any gas leaks during your installation?

 

[Agile]

Your old baxi may have been a gravity hot water system. They were never great!

Only 2 kW in the heat loss calculation is apportioned for hot water heating!

Most 3 bed semis are about 10-12 kW heat loss. A 15 kW boiler is usually adequate!

Over powered boilers are less efficient and over cycle!

Tony

 

[cantaloup63]

Over powered boilers are less efficient and over cycle!

Tony

How much can an overpowered boiler be "turned down" whilst maintaining a sedbuk A efficiency?

 

[diydad888]

I could do a pressure test but that would be on the whole gas line (inc cooker and fire in living room) back to the meter, I could isolate a smaller section, involving another break in the line that would need tested also.
I could do a bubble test as the last guy done..I mailny concerned to connect up all the water pipes and get a gas engineer to connect and test the boiler for correct running.

 

[diydad888]

Thanks for the advice, I guess I have got a boiler that is over sized due to my lack of experience , price £670 +V) was little different from the worcester 15...I could return it as not yet out of the box

 

[Agile]

To correctly size you need to do a whole house heat loss calculation.

Worcester do a range of boilers to suit every application. 12 Ri, 15 Ri, 18 Ri and 24 Ri. So you just pick the most appropriate one for the application. Usually the next larger.

Tony