• Welcome to PlumbersForums.net (formerly UKPlumbersForums.co.uk). Please login with your usual username and password. Or register for free if you haven't already done so.

Discuss Instant hot water heater before or after pump? in the Bathrooms, Showers and Wetrooms area at PlumbersForums.net

justin tuijl

New Member
Messages
12
Reaction score
0
Hi, I have a bespoke system in an old building I did myself. At the moment I have the pump before the instant hot water heater. I wondered if it would be better to put it after the pump? So it pumps cold into the heater, rather than pulls hot out of the heater. Thanks for any help.
 

Riley

S. Mod
Trusted
Plumber
GSR
Messages
10,622
Reaction score
3,451
What sort of pump? Tank fed cold? Check that heater can deal with pumped
 

chris watkins

Plumber
Messages
5,009
Reaction score
2,205
In simple terms pumps work best pushing rather than pulling, why do you ask?
Who designed your bespoke system Justin?

PS. welcome to the forum.
 
OP
justin tuijl

justin tuijl

New Member
Messages
12
Reaction score
0
Thanks for the welcome.

The pump is a twin impeller shower pump and the hotwater heater a Thermomate ELEX12 Instant Water Heater 12kW Tankless fed from a cold tank. I made the system, I did it by guesswork, first go at it.
 

Riley

S. Mod
Trusted
Plumber
GSR
Messages
10,622
Reaction score
3,451
Sounds dangerous mate. Why not just install an electric shower
 
OP
justin tuijl

justin tuijl

New Member
Messages
12
Reaction score
0
Sounds dangerous mate. Why not just install an electric shower
Unfortuntely I went one way with it. At the moment it works, just with the pump pulling through the water heater. I ended up with a non-power shower, kind of stuck with what I have now.
 

Riley

S. Mod
Trusted
Plumber
GSR
Messages
10,622
Reaction score
3,451
Doesn’t mean it’s not dangerous. What flow and pressure can the heater deal with. If it’s tankless are you pumping mains??
 
OP
justin tuijl

justin tuijl

New Member
Messages
12
Reaction score
0
Doesn’t mean it’s not dangerous. What flow and pressure can the heater deal with. If it’s tankless are you pumping mains??
I wish I knew the flow rate, I was puzzled over that.
 

chris watkins

Plumber
Messages
5,009
Reaction score
2,205
Unfortunately it is the 12kW heater that is the limiting factor here.
Why do you think most properties store hot water in cylinders.
 

chris watkins

Plumber
Messages
5,009
Reaction score
2,205
You will be lucky to get 6LPM @ 30deg C rise in temperature out of it.
I do hope you had someone who knows the wiring regs connect up the power to it, this is not a diy item.
 

Forum Sponsors

Corgi - Plumbing Supplies for Professional Plumbers

Plumbase - Plumbing Parts for Plumbers

Underflor Heating Systems by uHeat

Wetroom Supplies by Wetroom Store

Nicobond - Wetroom and Tiling Supplies

Corgi - Plumbing Supplies for Professional Plumbers

Top Bottom