Any good problem solvers out there?

[grahamdvd]

The rinsing out was to ensure the pipe work was free of debris and the cylinder was filling up fine

 

[HERTS P&D]

Post pictures of the cylinder and pipework.

Andy

 

[grahamdvd]

I will, do I have to upload them to a online photo storage? Like photo bucket? Or can I ad a link from my one drive?

But why would it work for 10 years in the position it's in and suddenly stop working?

 

[Jajodu]

The auto air vent float was stuck in the up position so consequently air was never released, pumps dont want air in them. I just replaced it, worked fine ever since. Could explain your problem.

 

[grahamdvd]

Thanks I will, but the air vent on mine is after the pump only on the hot water side

 

[Hot&Cold]

I was told it is suitable for fitting above the cylinder, there was no room next to the cylinder.

It depends on what the original supplied installation instructions say,some say it in pictures.Taking verbal advice is often misleading .

The previous pump worked for 10 years in the same place above the cylinder .

The pump may have been just about about working,sometimes the comment "iam surprised it worked in the first instance are mentioned" and 10 years there may have been changes to the hot & cold water system including unseen changes like restrictions.

As mentioned your pump has a factory fitted crossover/bypass tube approx 6mm diameter,this has to work to prevent nuisance whilst pumping against a dead end.

Have not seen your installation and have to consider its professionally installed and correctly maintained with decent material including outlets,otherwise we are on the hamster advice wheel

 

[dilalio]

My first thought was pump location.
And, are you sure it’s not the mixers causing the noise? Are they HP or LP?

 

[grahamdvd]

I have tomorrow off work so will sort some photos out.

I've double checked the pipe work and it all seems to Salamander spec.

Pump is 600mm above cylinder, the cold water tank is on a 900mm high shelf in attic so pump will be 1500mm below bottom of cold water tank

Hot water:

S flange from top of cylinder to a 500mm anti gravity loop then 600mm of vertical pipwork to pump.

Then out of pump and back to hot water feeds to house.

Cold water:

Separate cold water 22mm feed from cold water header tank, opposite end to ball valve and into pump then out of pump to tank fed cold water supplies.

 

[grahamdvd]

Just ran a bath tonight and if you turn on hot water tap on bath it makes the groaning noise.( from the pump)

Then run the pumped cold water tap on the same mixer and after 30 secs you can turn off the cold tap and the hot water runs fine?

So what influence does turning on the cold tap have on the hot water

 

[grahamdvd]

It's definitely coming from pump the pump stop and starts while making the noise too

 

[dilalio]

Imbalance between hot & cold!

 

[grahamdvd]

Thanks,

So how does imbalance work and how do you stop it?

Is it inbalance if you run both hot and cold together?

But if I'm only running hot it makes the noise? Turning on the cold stops the noise?

It seems that when you turn on the hot water tap the pump is running dry( air)?

Then turning on the cold tap fills the hot side of the pump with water ( using the crossover) and after 30 secs it runs normal?

I ran the bath tonight...I turned on the hot tap and it made the noise, so I turned on cold tap for 20 seconds to stop the noise.
Then I turned cold tap off and the hot tap was fine so ran bath with hot water for 10 mins.

I then turned hot tap off, and then tried to run more hot water and the noise came back?

So it seems it's the initial pumping of hot water, once you get rid of the noise and its pumping it works fine?

 

[dilalio]

The hot side is being starved of supply... for whatever reason via the hot water path... it has to be either a blockage, restriction, air or issue with the pipework, cylinder, fittings or loop.

Try swapping over the feeds to the pump as a quick test but be careful not to flush a toilet else you’ll get hot water in the cistern(s).

But it defo sounds like the hot route to the pump has an issue.

You could also try mains pressure (via a garden hose) to push the hot supply to the pump in reverse - through the loop - cylinder - and back up the hot outlet to the cws. It may be that there’s something wedged in direction of flow.

The pump is not getting primed on the hot side... until you add cold via the crossover.

I still think putting the pump on the floor would sort the problem - you could rig this up with some barrier pipe and fittings just to see... even if it’s outside the cupboard for a benchtest.

 

[grahamdvd]

Hi I did connect a mains water hose from cold water tank and flushed out the cylinder then replaced s flange and took all pipe work from s flange to pump off too and checked it. If I run the hot water with the pump turned off it flows fine? So you would think if there was a restriction it would not flow with just gravity? Thanks

 

[HERTS P&D]

It would flow with gravity if there was a partial blockage. But when the pump is activated the partical blockage is stopping the pump from fully functioning.

Andy