is 10mm pipe ok?

[IA76]

Hi

my house already had 11 rads fitted + a vaillant boiler which is rate up to apprcox 85,000 BTU's.

The pipe going to the rads is 10mm (microbore the plumber called it)

Anyway since i am redecorating and the rads have seen better days i decided to get new rads fited but I have decided to upgrade 4 of the 11 rads to double ones as the older ones did not heat the rooms enough. The total BTU's for the 11 new rads is about 50,000.

I had 2 peopl ein to give me a quote but they are giving me conflicting information.

A is saying that as I am changing some of the rads to doubles I need to have all the 10mm pipework in the house changed to 15mm stuff.

B is saying that it's ok for me to run the rads I want to the existing 10mm pipework and that 10mm piping is more common than people think.

So who is correct

Thanks

 

[chrishutt]

B

Subject to the proviso that there is a limit to the length of the run of 10mm tube that any particular radiator can be fed by. But unless your 10mm runs are exceptionally long (say more than 15 metres) in the case of the largest radiators, you can ignore this.

 

[PEDANTICVINDICTIVEMAN]

I use my own rule of thumb which is - 8mm pipes up to 8000btu's max 10mm pipes up to 10,000btu's , whether this is technically right or wrong I dont care, it always works for me.

 

[DP]

If existing rads are not heating the rooms sufficiently, I would want to find out why.

What setting are you running the boiler at, delta T or system water quality etc come to mind. Just because you are going to hang a double panel on the wall to replace the existing, does not mean you will get more heat out of the new radiator if the new rad is not getting the required amount of water. New double panel will in effect be looking for more water.

Existing radiator would have been calculated to replace the heat lost through the fabric of the room with outside at -1. If four of the new rads are to be oversized, can the boiler cope with this?

 

[IA76]

Thanks for the replies all.

CHRISHUTT , the longest run is probably about 10m

PEDANTICVINDICTIVEMAN , going by your rule i will be fine with 10mm

DP , i used various BTU calcs and they all showed me that some of the rads I had were tot small hence me changing to double ones.

My boiler is rated up to about 85,000 BTU's. The BTU of all my new rads inc the double ones is about 50,000.

 

[PEDANTICVINDICTIVEMAN]

If existing rads are not heating the rooms sufficiently, I would want to find out why.

What setting are you running the boiler at, delta T or system water quality etc come to mind. Just because you are going to hang a double panel on the wall to replace the existing, does not mean you will get more heat out of the new radiator if the new rad is not getting the required amount of water. New double panel will in effect be looking for more water.

Existing radiator would have been calculated to replace the heat lost through the fabric of the room with outside at -1. If four of the new rads are to be oversized, can the boiler cope with this?

Not if Mr Dickhed diyer got all his gear from wickes/b&q or it was a £1500.00 for 5 rads and a combi crappp job

 

[IA76]

If existing rads are not heating the rooms sufficiently, I would want to find out why.

What setting are you running the boiler at, delta T or system water quality etc come to mind. Just because you are going to hang a double panel on the wall to replace the existing, does not mean you will get more heat out of the new radiator if the new rad is not getting the required amount of water. New double panel will in effect be looking for more water.

Existing radiator would have been calculated to replace the heat lost through the fabric of the room with outside at -1. If four of the new rads are to be oversized, can the boiler cope with this?

Not if Mr Dickhed diyer got all his gear from wickes/b&q or it was a £1500.00 for 5 rads and a combi crappp job

the previous owner of my house definatley skimped on the rads. none of them are even the same brand so i'm changing them all in 1 go