Running twin impeller pump off indirect hot water without a surrey flange, bad idea?

[Bob Hill]

Hi all,

I'm pretty sure i'm correct here and not going mad but wanted to check before causing problems.

My mum is looking to get some bathroom work done and the company she is thinking about appear to be suggesting sighting a twin impeller pump under that bath to feed the shower and taps.

They have made no mention of adding a surrey (or any other type) flange to her vented indirect hot water cylinder. It appears they just want to attach it to the existing hot and cold feeds under the bath and be done with it.

Now as far as i'm concerned this seems a total no no and a recipe for disaster because the pump could get air in it from the top of the cylinder (hence why one fits a surrey flange) which would damage it. Not just that but the hot and cold bath pipe work are downstream from both the basin and toilet meaning that if either are used whilst the bath is filling then surely there is a good chance of air being sucked into the system by the pump downstream of the toilet or sink.

Thoughts?

Thanks in advance!

 

[turnpin]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

Whatever pump is fitted if it's not fitted as per manufacturers instruction's it will deem any guarantee null and void ......regards Turnpin:yes:

 

[Bob Hill]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

Hi Turnpin, thank for your response. I'll take it that you think i'm right to be concerned here.

I'm just looking at various manufacturers install instructions and both Salamander and Stuart turner pumps say they must have dedicated air free supplies whilst grundfos say you 'can' supply direct from the cylinder but this increases the risk of air getting in and causing issues.

Unless they're planning on installing some magic pump it looks like they are being cheeky then....

 

[turnpin]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

Pumps fitted under baths are also not really the best place to be fitted poor access and an out of sight out of mind mentality means these Guy's will be a long way down the road when the proverbial hits the fan.......try and find out what pump they are thinking of using and download the m.i installation manual.......or maybe get another quote from one of the Guy's/girl's on here......best of luck regards Turnpin:yes:

 

[1Steven]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

I never put 240 volts under the bath! That's shocking!

 

[Riley]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

Are these guys definitely plumbers and not builders

 

[Bob Hill]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

They're an adaptions company putting In low access baths etc but its looking like they might not have all the technical knowledge they need. On the other hand there may have been some miscommunication or mistake. I think ill need to speak with them and see because that might clear it up or make clear they don't know what they're on about.

 

[Riley]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

To be honest, technical knowledge aside they clearly aren't bothering to follow manufacturers instructions. Unless they are fitting some weird Chinese made rubbish I think you'll find most twin pumps over here require a flange or dedicated feed. I would strongly suggest you get a second/third quote

 

[Old Account]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

The pumps shouldn't be installed not further then 4 m from the cylinder. But Stuart turner would accept to T off from the hot water expansion pipe if a flange isn't practical.

But if you do connect at the hot water expansion pipe you will to make sure that the cold water storage tank is at least 1m above the hot water cylinder.

But as you mentioned it's always better to get the right flange but not only for warranty purposes

Pumps fitted under baths are also not really the best place to be fitted poor access and an out of sight out of mind mentality means these Guy's will be a long way down the road when the proverbial hits the fan.......try and find out what pump they are thinking of using and download the m.i installation manual.......or maybe get another quote from one of the Guy's/girl's on here......best of luck regards Turnpin:yes:

 

[Riley]

Re: Running twin impeller pump off indirect hot water without a surrey flange, bad id

Just don't give the manufacturers the opportunity to wriggle out of it