push fit or compression fittings for waste pipe

C

Claire1999

Joined

19 Apr 2020

Messages

9

Reaction score

0

Country

• 23 May 2021

• #1

Hi quick question
I used two 90 push fits bends to connect the 40mm waste to down pipe. Now when every hot water goes down it makes a knocking/creaking noise that is driving me mad. Guessing it is from heat expansion.
Do compression joins have the same problem? As I was just thinking of changing them over.
Also I check its not actually knocking on anything and it's not the soil pipe.
Thanks

 

T

terryplumb

Joined

8 May 2017

Messages

9,397

Reaction score

2,337

Country

• 23 May 2021

• #2

Sounds like the pipe or elbows maybe rubbing against something.

 

C

Claire1999

Joined

19 Apr 2020

Messages

9

Reaction score

0

Country

• 23 May 2021

• #3

Has 5cm clearent all round. I've even sat watching it, to see if it could have been hitting something with hot water going down but nothing moving and the noise still starts.
Also then put insulation around it but no improvement.

 

T

terryplumb

Joined

8 May 2017

Messages

9,397

Reaction score

2,337

Country

• 23 May 2021

• #4

Can you show us pics of the set up ?

 

Alec_t

Joined

18 Mar 2017

Messages

1,191

Reaction score

244

Location

Wales

Country

• 23 May 2021

• #5

Claire1999 said:

Guessing it is from heat expansion.

Click to expand...

Agreed. I doubt it's anything to do with the type of joint/bend. Somewhere along the pipe run there will be a pipe support/clip which grips/releases/grips/releases .... creating the sound.