humming rad

[jambo]

just completed an 8 radiator system running off a 37cdi combi everything fine but bathroom rad 600x700 humming coming from rad like a blow heater its running off 22mm to 8mm with danfros trvs & lockshield if you shut the lockshield off noise gon even slightly open it humming back checked below rad for kinked pipe etc all fine any ideas guys cheers

 

[street elbow]

Jambo,

I would have thought the problem is caused by the water speeding along happily in a 22mm pipe then all of a sudden that same amount of water has to get through an 8mm pipe,

I think you need to increase the pipe size to 10 or 15 mm and you will find the water flows silently through the pipes.

David

 

[jambo]

i see what your sayin but the other 7 rads are 8mm to but big but the manifold is directly below the hummin rad so its hitting that rad first off the 22mm then that rad so guess ur prob right

 

[oldplumber]

I only ever rip out micro bore sytems why are you putting them in Jambo, water velocity versus pipe size only ever gives you a nasty noisy system, thats why the nice plumbing suppliers invented barrier pipe on coils, so you dont have to use micro bore any more

 

[newbie1]

each to their own but why run in 8mm when you have 22mm feed surely it would have made more sense to use 15mm for the tees/drops

 

[GreenArmy]

Do people still fit micro-bore? Nice to see you back Jambo, ive missed your posts.

 

[stevetheplumber]

Do people still fit micro-bore? Nice to see you back Jambo, ive missed your posts.

ninty percent of new builds are 10mm usually buried behind dry lining
10mm system work well and a lot of the problems encountered with microbore the first time round have been eliminated systems are cleaned and fernoxed so no problems with corrosion or muck in the pipes plastic doesnt get flattened on site like copper used to and most systems are sealed so no pump over or air getting in to cause corrosion or algea
using a manifold sytem means no joints below floors as ech rad is run seperatly
no pipe work needs to go in the screed as it can be fed from above in one length behind dry lining or in wall voids

jambo have you tried taking the head of the trv see if its that cuasing the noise or try shutting the ls down to slow flow

 

[jambo]

tryed to tell the customer that that but he did not want the 8mm remover but rest of house is fine just that one point taken though

try telling that to the customer on a stricht budget

shut the lockshield down fully no hummin so opened it half a turn reduced the noise but am still not happy bout it

 

[payney1974]

is it a new trv jambo? Old ones weren't bi directional!

 

[Billy Bob Bob]

8mm if anything works ok but can be prone to leaks after getting knocked etc nothing wrong with mini bore i suspect[and i am not pointing fingers]people who dont like it are not skilled enough to use it]but 10mm is a lot better i think your biggest problem is you have a faulty trv