Vaillant ecotec hw circulation pump

G

GrogSym

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Hello! System as follows:
Ecotec 46kw to heat exchanger
4 pumps - 3 heating zones and hw
Tank is a Tempest solar 300 (plumbed for heating through boiler only)
Controlled by Sensocomfort and 2 slaves

Since having the system installed a year ago, I've had a return hot water leg and pump fitted to the hw tank to allow for hot water to be circulated at certain times of the day. However the plumber and electrician that have fitted it (as part of building works) aren't sure how to configure it.

Now I realise it's far from an average install, but wondered if anyone here would be able to advise on how to wire and control the new Grundfos circulating pump, if it's even possible?

Many thanks,

Greg
 
The Vaillant specific control system includes the facility to run the circulation pump, when ever you set the times for it to run. I would assume it also checks the water is hot, before running the pump.

A good compromise, would be to simply have the pump on a separate timer clock, to run when you normally have a demand for hot water. You could improve on that, by have an extra stat on the HW cylinder, which only enabled the pump, when the water was actually hot.
 
Take it the pump is not ordinary circulator used in heating systems- correct one is often known as bronze pump
 
DP said:
Take it the pump is not ordinary circulator used in heating systems- correct one is often known as bronze pump
Click to expand...
Thanks! That's a good question - it's a Grundfos UPS3 15-50/65. Does it make a difference?
I've wired the pump today as per wiring instructions for 'secondary circulation' (ie have wired it to x13 on boiler) and have set the controls for 'circulation weekly planner' but only get 6 volts coming to pump (the live is showing 240 at the boiler and pump end, the neutral seems to be switched).
If it is possible to have it without a separate timer it would be much neater, but that's always a fall back...
 
IMG_20220129_174226.jpg IMG_20220129_174232.jpg IMG_20220129_174243.jpg IMG_20220129_174256.jpg
 
Doesn't look like a bronze pump to me & yes it does make a difference. Some of the pumps designed for the job have built-in circuitry to 'learn' the patterns of dhw use. If use is continuous or unpredictable then either leave it run full-time or look at some other means of triggering (PIR sensors on the way to the bathrooms or showers?).
 
I've spent the last while reading, and now see why it needs to be a bronze pump (corrosion). I've also read that the return leg should not be in plastic - is that correct? If so, it's game over!
 
GrogSym said:
I've spent the last while reading, and now see why it needs to be a bronze pump (corrosion). I've also read that the return leg should not be in plastic - is that correct? If so, it's game over!
Click to expand...
None of the placcie pipe suppliers have certified their stuff for use in dhw circulation systems so in terms of compliance with water bylaws and probably building regs then yes you're out of luck- your plumber really should have done a bit of research before firing a load of tube around the place.
I assume it wasn't the same plumber that did the original install.....that pushfit elbow coming off the cylinder is amateur night out.
EDIT The pump needs to be fixed to something as well not just hanging off the pipework. Rubbish bodge on a nice neat system.
EDIT 2 That pump is not only not suitable, it's been mounted in the wrong plane- pump axis has to be horizontal or near as, they've chucked that in nearly vertical but not quite, maybe he tied his horse to it & it bolted?
 
oldbutnotdead said:
None of the placcie pipe suppliers have certified their stuff for use in dhw circulation systems so in terms of compliance with water bylaws and probably building regs then yes you're out of luck- your plumber really should have done a bit of research before firing a load of tube around the place.
I assume it wasn't the same plumber that did the original install.....that pushfit elbow coming off the cylinder is amateur night out.
EDIT The pump needs to be fixed to something as well not just hanging off the pipework. Rubbish bodge on a nice neat system.
EDIT 2 That pump is not only not suitable, it's been mounted in the wrong plane- pump axis has to be horizontal or near as, they've chucked that in nearly vertical but not quite, maybe he tied his horse to it & it bolted?
Click to expand...
You wouldn't believe this plumber, he was part of a larger building firm. He originally had the pump running the wrong direction. Everything, and I mean everything, that he did had to be redone... I'm worked for the pipes under the floor!
 
Have you paid him? If yes, demand in writing a full refund- he's supplied and badly installed the wrong stuff for the job. Give him 14 days then small claims (or statutory demand can work quite well).
 
It makes me sad, as you tend to get one shot of doing these things properly. The so called plumber has also run the cold water kitchen feed near the heating pipes under the kitchen floor, so every time we need cold water at the kitchen tap, we have to run it for 40ish seconds. A little reminder of my unhappy kitchen renovation for 20 years to come!
I'll email them now. I think £500 should cover it...
 
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