Hand basin hot water flow reduced and pulsing

Forums › Home Workshop DIY › Hand basin hot water flow reduced and pulsing

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#284270 10-Apr-2021 15:00

Over the last month the bathroom hand basin hot water flow from the faucet has decreased a little and pulsates slightly, at about a 0.7sec period.

Having read on GZ of failures of under sink flexi-hoses, I am beginning to wonder if the hot water hose is delaminating.

Hot water flow from the same under floor pipe work to the shower and to the bath appears to remain unaffected.

There is a tempering valve back at the hot water cylinder that may affect flow but as I have mentioned the shower and the bath flows appear unaffected.

The hot water cylinder is about 3 to 4 metres away from the bathroom outlets and I doubt that the amount of water in the under floor pipe work would pulsate very fast.

I have checked the faucet outlet nozzle filter and I have not seen any gunge.

I took a brief look under the basin to see if the flexi hose could be replaced, but it looks like the hose dissapears into the faucet and may be an integral part of the faucet.

Here are a few pictures related to the issue.

The following snapshots were taken from a video and show the small change of flow and deflection from the faucet nozzle. Not much to go on....

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

1 | 2

729 posts

Ultimate Geek

#2690623 10-Apr-2021 15:22

Does it still do it with the filter removed? I’ve replaced these before when pressure has dropped and it’s solved that problem straight away, they seem to clog up internally and look fine otherwise. I’m far from a plumber though!

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2690631 10-Apr-2021 15:59

Kraven: Does it still do it with the filter removed? I’ve replaced these before when pressure has dropped and it’s solved that problem straight away, they seem to clog up internally and look fine otherwise. I’m far from a plumber though!

I get pretty much the same slower flow with the faucet outlet filter on or off. I don't know if there is a filter further up stream.

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

hsvhel

1237 posts

Uber Geek

ID Verified

#2690705 10-Apr-2021 20:00

air getting into the tap from a worn gasket?

Any seepage from the tap when in use, or when on full hot does it take a little longer to supply?

sounds like its sucking air during operation

Referral Link Quic

Free Setup use R502152EQH6OK on check out

mkissin

388 posts

Ultimate Geek

ID Verified

#2690710 10-Apr-2021 20:19

That flexi hose will be replaceable. It has a screw fitting that goes into the bottom of the tap. I've never replaced one though, you might need to remove the tap to get at it.

timmmay

20574 posts

Uber Geek

Trusted

Lifetime subscriber

#2690718 10-Apr-2021 20:59

Take the tap off the basin to replace the hose. Better yet get a plumber to do it, if you haven't done it before it can be a MASSIVE pain and take a day. I did this with my kitchen sink and one thing led to another, ended up replacing the perfectly good sink tap because I couldn't find replacement hoses the right size and the old hoses were too worn to put back.

While the plumber is there ask about the pulsating thing.

duckDecoy

896 posts

Ultimate Geek

Subscriber

#2690725 10-Apr-2021 21:46

Sell your house and move into another that doesn't have this issue.

Problem solved

gzt

17104 posts

Uber Geek

Lifetime subscriber

#2690805 11-Apr-2021 10:05

In the old style taps this was a symptom of a worn or broken washer mechanism.

Equinox IT

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.

Bung

6477 posts

Uber Geek

Subscriber

#2690807 11-Apr-2021 10:16

Is the system mains pressure or does it have a pressure reducing valve? If it has a reducing valve the pulsing could be coming from it and related somehow to the flow rate. See what happens to the pulsing if you start turning on another hot tap as well.

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2690825 11-Apr-2021 11:19

duckDecoy:

Sell your house and move into another that doesn't have this issue.

Problem solved

Ha Ha

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

RunningMan

8953 posts

Uber Geek

#2690827 11-Apr-2021 11:26

Do you have equal hot/cold pressure? Could swap the hot/cold connections temporarily, that will help isolate where the problem is.

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2690828 11-Apr-2021 11:27

mkissin:

That flexi hose will be replaceable. It has a screw fitting that goes into the bottom of the tap. I've never replaced one though, you might need to remove the tap to get at it.

The tap is at least 7 years old. I am thinking that for $80 to $120 I might just replace the whole faucet.

Trying to find the correct flexi hose may be a problem.

First I will disconnect the hot flexi hose (after turning off the water :-) and then check for flow from the wall connection.

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2690830 11-Apr-2021 11:42

Bung: Is the system mains pressure or does it have a pressure reducing valve? If it has a reducing valve the pulsing could be coming from it and related somehow to the flow rate. See what happens to the pulsing if you start turning on another hot tap as well.

Hot water tank has a cold feed thru a pressure reducing valve.

Turning on the bath hot water reduces the basin flow and pulsing.

If I turn off the basin tap and turn it back on then there is very little flow.... as if the bath flow has robbed the basin flow.

Maybe the pressure reducing valve is getting tired and not adusting/increasing flow with pressure change.

Looks like the cylinder dates back to 2001 and maybe the pressure reducing valve too...

The bathroom plumbing may be a bit more recent. I have been in the house for 7 years now.

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2690833 11-Apr-2021 11:49

gzt: In the old style taps this was a symptom of a worn or broken washer mechanism.

Yes... I remember that. The jumper carrying the washer would literally 'jump' and oscillate.

On some taps in an old house the taps could be adjusted so that this would cause significant water hammer noise all around the house. The water plumbing was in galvanised pipes.

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

Bung

6477 posts

Uber Geek

Subscriber

#2690886 11-Apr-2021 14:59

Gordy7:
Maybe the pressure reducing valve is getting tired and not adusting/increasing flow with pressure change.

Looks like the cylinder dates back to 2001 and maybe the pressure reducing valve too...

Sometimes there can be a fine mesh filter on the cold supply and/or a filter before the reducing valve.

Gordy7

1906 posts

Uber Geek

ID Verified

Lifetime subscriber

#2713166 26-May-2021 13:10

I now have good hot water flow in my bathroom hand basin again 😀

After waiting 3 1/2 weeks for a plumber, I cancelled and decided to have a look myself.

The culprit turned out to be a gunged up flow restricter installed on the low pressure hot water side.

Cowboy plumber who did the installation must have needed a nipple and decided to use the restricter.

Of course it was the high pressure cold water side that actually needed a restricter.

I did not refit the restricter.

I fitted a couple of ball valves to make hand basin faucet maintenance easier next time and to help restrict cold water flow.

After a blow out with a compressor the restricter does not look too bad now:

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

1 | 2