Circulating Pump settings

Wearb · 08-12-2018 4:43pm #1

I replaced the circulation pump on this which was the main reason for the visit. Just got a call to say rads are slow to heat. I used an A rated 5M pump and set it to auto. I expect I need to use a different setting? 26kw boiler with 5 single and 5 double rads and DHW. No zones or trvs.
Pump has cp1 and 2, pp1 and 2 and 3 speed options.
Any one know which setting I should use. Perhaps pp1 at 2 speed?

John.G · 08-12-2018 4:54pm

Wearb wrote: »

I replaced the circulation pump on this which was the main reason for the visit. Just got a call to say rads are slow to heat. I used an A rated 5M pump and set it to auto. I expect I need to use a different setting? 26kw boiler with 5 single and 5 double rads and DHW. No zones or trvs.
Pump has cp1 and 2, pp1 and 2 and 3 speed options.
Any one know which setting I should use. Perhaps pp1 at 2 speed?

What make pump/model?. and what did it replace ( what speed setting was this on ?)

Wearb · 08-12-2018 5:47pm

John.G wrote: »

What make pump/model?. and what did it replace ( what speed setting was this on ?)

Old one set at 2. Pic of box from new one.

agusta · 08-12-2018 6:49pm

Was there any slight leak in the old pump valves

Wearb · 08-12-2018 6:58pm

agusta wrote: »

Was there any slight leak in the old pump valves

Not until I closed them. I only had 1" valves with me (3/4" on it), so I need to go back and change them ...if the weep hasn't stopped by then. I will change them anyway sooner or later.

How would you set up the A rated pump? I know that no plumbers around here does the calculations. They just buy the stocked pump, which is always a 5M and set it at two for a medium sized house, 3 if bigger and turn it back one if it's noisy.

Just found the PDF for the pump that I put on it.
http://www.sanbrafyffe.ie/pdfs/specifications/tucson-a.pdf

Wearb · 08-12-2018 7:02pm

Even more details on the pump here.

http://media.brintex.com/Occurrence/174/Brochure/4729/brochure.pdf

John.G · 08-12-2018 7:28pm

Wearb wrote: »

Old one set at 2. Pic of box from new one.

As far as I can interpret the pump curves, PP1 will operate between 2M & 1M and PP2 between 4.5M and 2.25M.....I don't think that you can set PP1 or PP2 on any particular "speed". I would suggest PP2 and see how that goes. If the rads are still slow to heat then change to FP2 which will try and maintain a constant 4.5M...if all else fails you can go to constant speed iii (ii is probably a little low as it corresponds to a 3.2M pump).
I installed a Wilo Pico Yonis 1-6 a few weeks ago and settled on a PP setting of 4.0M which gives a flow rate of 12LPM @ 3M head with all rads and coil full on which gives a 20 Kw boiler a temperature rise of ~ 22/24C. I have 6 double rads & 4 singles.

agusta · 08-12-2018 7:50pm

its annoying not having the pump valves,i probably would have fitted a 6m pump and put it on constant speed 2.
With the 5m pump, i would have put it on constant speed 3.If the house was zoned and thermostatic valves id have set it on pp2.Tested heating and see how rads heated etc.Having said that my knowledge of pump curves is limited.

John.G · 08-12-2018 7:57pm

Wearb wrote: »

Not until I closed them. I only had 1" valves with me (3/4" on it), so I need to go back and change them ...if the weep hasn't stopped by then. I will change them anyway sooner or later.

How would you set up the A rated pump? I know that no plumbers around here does the calculations. They just buy the stocked pump, which is always a 5M and set it at two for a medium sized house, 3 if bigger and turn it back one if it's noisy.

Just found the PDF for the pump that I put on it.
http://www.sanbrafyffe.ie/pdfs/specifications/tucson-a.pdf

I did mine in the following manner (but I have all the time in the world to play around with the settings) I measured the boiler deltaT with everything opened up fully with the old pump in service and then just tried different PP settings until I got the same DeltaT with the Wilo. The higher you set the PP the higher the flow rate for any given condition. If I was in the trade and in a hurry I would be inclined to use the CP rather than the PP settings and if available set it at between 3.5M and 4.5M. or just go to the tried and trusted fixed speed setting of 2 or 3.

Wearb · 08-12-2018 7:57pm

John.G wrote: »

As far as I can interpret the pump curves, PP1 will operate between 2M & 1M and PP2 between 4.5M and 2.25M.....I don't think that you can set PP1 or PP2 on any particular "speed". I would suggest PP2 and see how that goes. If the rads are still slow to heat then change to FP2 which will try and maintain a constant 4.5M...if all else fails you can go to constant speed iii (ii is probably a little low as it corresponds to a 3.2M pump).
I installed a Wilo Pico Yonis 1-6 a few weeks ago and settled on a PP setting of 4.0M which gives a flow rate of 12LPM @ 3M head with all rads and coil full on which gives a 20 Kw boiler a temperature rise of ~ 22/24C. I have 6 double rads & 4 singles.

Do you mean change to Cp2? It doesn’t have a Fp setting.

John.G · 08-12-2018 7:58pm

Wearb wrote: »

Do you mean change to Cp2? It doesn’t have a Fp setting.

Sorry, yes, I meant constant pressure.

Wearb · 08-12-2018 9:14pm

John.G wrote: »

I did mine in the following manner (but I have all the time in the world to play around with the settings) I measured the boiler deltaT with everything opened up fully with the old pump in service and then just tried different PP settings until I got the same DeltaT with the Wilo. The higher you set the PP the higher the flow rate for any given condition. If I was in the trade and in a hurry I would be inclined to use the CP rather than the PP settings and if available set it at between 3.5M and 4.5M. or just go to the tried and trusted fixed speed setting of 2 or 3.

I suppose that you realise that the original pump would most likely not have been sized correctly either. It would have been fitted as I described above.

Plumbers around here will tell you -correctly- that they’ve been doing it like that for years without problems.
And I suppose that in the average domestic system it does work out fine.

I only once fitted an A rated pump once before and that was for a plumber that couldn’t get around to it. That was set to auto and I didn’t hear if it caused problems.

I just wondered if there was a rule of thumb guide for those new pumps. I did read that one of the settings shouldn’t be used with zones or trvs.

anthonyos · 08-12-2018 9:20pm

System may need balancing or there is a possibility that there was issues before you arrived. Heatmercants do an own brand pump that is 7 metre head.i have been a plumber for many years and have never got in to sizing and that crack and have never had any problems

anthonyos · 08-12-2018 9:23pm

Was the old one seized

Wearb · 08-12-2018 9:50pm

anthonyos wrote: »

.i have been a plumber for many years and have never got in to sizing and that crack and have never had any problems

Domestic heating systems fairly tolerant of of the variation in pumps and the merchants stock the ones that have proven to work.

System may need balancing or there is a possibility that there was issues before you arrived. Heatmercants do an own brand pump that is 7 metre head

It wasn't fully seized. There was a little heat coming through the pump, but from putting my hand on both sides of it, the output from the pump was way too low. It was eventually tripping the Hi limit.

I wouldn't be surprised if the system needed balancing. When I was there the coil valve was fully open, but I suspect that it was tampered with by the customer when the pump went.

Is the Heatmerchants one digital and if so, what is the usual setting for them?

Wearb · 08-12-2018 9:55pm

John.G wrote: »

Sorry, yes, I meant constant pressure.

Something that I forgot to add and has come back to me now. I noticed that on auto the pump was using about 20W, something that at the time struck me as too little in a house 40 hours without heat. however I left it at auto, assuming that the A rated pump was way more efficient than my own ancient 80W one.

John.G · 08-12-2018 10:39pm

Wearb wrote: »

I suppose that you realise that the original pump would most likely not have been sized correctly either. It would have been fitted as I described above.

Plumbers around here will tell you -correctly- that they’ve been doing it like that for years without problems.
And I suppose that in the average domestic system it does work out fine.

I only once fitted an A rated pump once before and that was for a plumber that couldn’t get around to it. That was set to auto and I didn’t hear if it caused problems.

I just wondered if there was a rule of thumb guide for those new pumps. I did read that one of the settings shouldn’t be used with zones or trvs.

Because there are/were "only" 3 speed settings in the old pumps then whatever setting was selected it wouldn,t be perfect so the tendency was to oversize and run it at speed 2 or if more rads added to the system run at speed 3.
The A rated pumps are supposed to give the best of all worlds, ~~ 2 to 3 times more efficient under all conditions with additional further savings if properly set up on PP control, sufficient head to satisfy full heating needs and then modulation as zones/TRVs shut down as lower head required then = lower power, my old Salmson ran at a constant 46 watts (speed 2) but was/is still in perfect condition after 18 years and if/when the Wilo expires then I will re install it. I do see a reduction of 2/3 watts as TRvs shut down and ~ 5 watts if cylinder coil only in service. It is recommended to use CP for underfloor heating as the head required is supposedly more constant than with rads.

corkgsxr · 08-12-2018 10:40pm

Tuscan pumps are ****. Sorry.

I've tried various. Stuck to grundfos after a few years. And I've no issues with pumps anymore

Wearb · 08-12-2018 10:43pm

corkgsxr wrote: »

Tuscan pumps are ****. Sorry.

I've tried various. Stuck to grundfos after a few years. And I've no issues with pumps anymore

Fingers crossed so.

John.G · 08-12-2018 11:36pm

Wearb wrote: »

Something that I forgot to add and has come back to me now. I noticed that on auto the pump was using about 20W, something that at the time struck me as too little in a house 40 hours without heat. however I left it at auto, assuming that the A rated pump was way more efficient than my own ancient 80W one.

It will be interesting to see the wattage if/when you change to PP2 or CP2 or constant speed 3.

Wearb · 08-12-2018 11:51pm

John.G wrote: »

It will be interesting to see the wattage if/when you change to PP2 or CP2 or constant speed 3.

I did run through them before settling on auto. I remember that pp2 was about 40w

John.G · 09-12-2018 12:37am

Wearb wrote: »

I did run through them before settling on auto. I remember that pp2 was about 40w

That's a pretty hefty power draw, I would have expected that on a CP2 setting, it should certainly satisfy the rads/cyl coil requirements.

Wearb · 09-12-2018 11:05am

John.G wrote: »

That's a pretty hefty power draw, I would have expected that on a CP2 setting, it should certainly satisfy the rads/cyl coil requirements.

I wouldn’t be 100% certain that it was pp2, but thought it was. When I saw the low consumption on auto, I just cycled through the other settings to see how auto compared and then returned it to auto.

I don’t think these pumps modulate down as the temperature on return rises? Since trying to understand all the settings on this I have read of ones that do this.

John.G · 09-12-2018 12:54pm

Wearb wrote: »

I wouldn’t be 100% certain that it was pp2, but thought it was. When I saw the low consumption on auto, I just cycled through the other settings to see how auto compared and then returned it to auto.

I don’t think these pumps modulate down as the temperature on return rises? Since trying to understand all the settings on this I have read of ones that do this.

It could have been PP2, as you increase the PP setting the power consumption gets closer to the same CP setting and the opening/closing of zone valves has a much bigger effect on the power consumption as the slope of the PP curve gets steeper with increasing PP. I would venture that if you opened/closed the coil balancing valve (if not zoned) that you could see ~ 5W difference if on PP4.5

Re the Auto setting power consumption of 20W, I would have thought that (20W) would have given quite reasonable circulation through the rads etc even though I know that each house heating circuit is different, your system, 5D+5S rads isn't hughly different from mine, 6D+4S, power consumption ~ 20W on PP4.0 all rads and cylinder coil are performing fine with no balancing of either, I suppose that's what makes these pumps so interesting in their reaction to different systems and may even highlight some abnormal restrictions?, I think some pumps actually display the flow rate which would be extremely helpful.

No, these pumps don't modulate on temperature.

I will revert later to your post re the HM pump.

John.G · 09-12-2018 2:57pm

Wearb wrote: »

Domestic heating systems fairly tolerant of of the variation in pumps and the merchants stock the ones that have proven to work.

It wasn't fully seized. There was a little heat coming through the pump, but from putting my hand on both sides of it, the output from the pump was way too low. It was eventually tripping the Hi limit.

I wouldn't be surprised if the system needed balancing. When I was there the coil valve was fully open, but I suspect that it was tampered with by the customer when the pump went.

Is the Heatmerchants one digital and if so, what is the usual setting for them?

The HM 4-7 is I think a re badged DAB Evosta 4-7. It has 6 PP settings and 3 constant speed settings but no CP settings. Of the 6 PP settings, setting 5 &6 are probably the most applicable, PP5 is 3.8M to 1.9M & PP6 is 5.0M to 2.5M. The three constant speeds are (1) 4.2M, (2) 5.5M & (3) 7.0M.

I would suggest either PP6 or constant speed 2.

http://www.heatmerchants.ie/v4/581ae913-e1fb-435e-a88b-ded312da5b38/uploads/HM%20PROflyer.pdf

Wearb · 09-12-2018 3:36pm

John.G wrote: »

The HM 4-7 is I think a re badged DAB Evosta 4-7. It has 6 PP settings and 3 constant speed settings but no CP settings. Of the 6 PP settings, setting 5 &6 are probably the most applicable, PP5 is 3.8M to 1.9M & PP6 is 5.0M to 2.5M. The three constant speeds are (1) 4.2M, (2) 5.5M & (3) 7.0M.

I would suggest either PP6 or constant speed 2.

http://www.heatmerchants.ie/v4/581ae913-e1fb-435e-a88b-ded312da5b38/uploads/HM%20PROflyer.pdf

Coincidentally I was just looking at the pdf for that dab pump before lunch. Perhaps it’s well ranked in a google search.

Here is where I’m trying to get to with all my reading (and I think that to a large extent you have answered it). Most houses I visit are roughly the same size and either bungalows or dormers. Most have 3 zones and or trvs. I would like to be able to know what the most appropriate pump settings are for those houses.
I think that I’m slowly getting there. To be more accurate I just need to get my gathered information together and work out the max velocity for the pipework, head per meter, length, fittings etc. I may never get around to this and just stick to the tried and trusted 5,6 or 7m pump.

John.G · 09-12-2018 6:25pm

Wearb wrote: »

Coincidentally I was just looking at the pdf for that dab pump before lunch. Perhaps it’s well ranked in a google search.

Here is where I’m trying to get to with all my reading (and I think that to a large extent you have answered it). Most houses I visit are roughly the same size and either bungalows or dormers. Most have 3 zones and or trvs. I would like to be able to know what the most appropriate pump settings are for those houses.
I think that I’m slowly getting there. To be more accurate I just need to get my gathered information together and work out the max velocity for the pipework, head per meter, length, fittings etc. I may never get around to this and just stick to the tried and trusted 5,6 or 7m pump.

You may find the attached link of interest: http://www.tasonline.co.za/toolbox/pipe/velfirc.htm

You can quickly calculate pipe velocities,dynamic head,friction loss, and orifice sizing.
rem (approx) 1/2"qual pex ID=11.3MM. 3/4"qual pex ID=16.7MM & 3/4" copper ID=19.0MM. I cant find a bit of 1/2" copper pipe just now to measure its ID.

Wearb · 09-12-2018 6:32pm

John.G wrote: »

You may find the attached link of interest: http://www.tasonline.co.za/toolbox/pipe/velfirc.htm

You can quickly calculate pipe velocities,dynamic head,friction loss, and orifice sizing.
rem (approx) 1/2"qual pex ID=11.3MM. 3/4"qual pex ID=16.7MM & 3/4" copper ID=19.0MM. I cant find a bit of 1/2" copper pipe just now to measure its ID.

Thanks. Just had a look. How do I get flow rate?

John.G · 09-12-2018 7:52pm

Wearb wrote: »

Thanks. Just had a look. How do I get flow rate?

You have to input the flow rate, the pipe diameter, the pipe length and the material, the formula will then give you the friction loss. you would need to know the flow rates in the different pipes before and after they branch off to the rads or whatever....not a easy task, you would have to draw a line diagram from and to the boiler to the various rad tails etc and input the flowrates etc etc. I only posted it from a interest point of view really as it shows you the dramatic effect on the friction losses that using small bore pipework has which means higher pump heads required etc but as you say yourself just go for a 5 or 6 M pump, set it to a fairly high PP of 4.5 to 6 if available, if not, just put it to constant speed 2 or 3 and away you go, I think that some of these smart pumps now have so many bells and whistles that they can confuse the basics but no matter how clever or not they are then all of them will have the traditional 3 speed setting to fall back on as you can't be sitting there all day when you could be making a few bob on another job.

Wearb · 09-12-2018 7:54pm

John.G wrote: »

You may find the attached link of interest: http://www.tasonline.co.za/toolbox/pipe/velfirc.htm

You can quickly calculate pipe velocities,dynamic head,friction loss, and orifice sizing.
rem (approx) 1/2"qual pex ID=11.3MM. 3/4"qual pex ID=16.7MM & 3/4" copper ID=19.0MM. I cant find a bit of 1/2" copper pipe just now to measure its ID.

I have been working on this and It seems that modern houses with each rad plumbed individually back to the hotpress (in 1/2" pex) manifolds require a a larger pump than those with the old way of plumbing. The manifolds use a lot more piping.

John.G · 09-12-2018 8:59pm

Wearb wrote: »

I have been working on this and It seems that modern houses with each rad plumbed individually back to the hotpress (in 1/2" pex) manifolds require a a larger pump than those with the old way of plumbing. The manifolds use a lot more piping.

They do but I would think that the 3 or 4; 1/2" parallel circuits would have less of a pipe friction loss than than 2 X 3/4 ins headers with 1/2" short rad tails.

Circulating Pump settings

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