Auto Adjustable circulation pump based on open zones?

paul-2008

Hi all,

Looking for some advise on a circulation pump if anyone could recommend..

Currently living in a bungalow that has OFCH with three zones (living/kitchen area (1) Bedroom area (2) and Hot Water (3)) I find myself constantly having to manually adjust the pump speed based on what zones I have turned on i.e if heating all zones speed 3 is required but if just heating the bedroom zone the rads are very noisy due to the high speed and I adjust back to speed 2.

So my question is, is it possible to get a pump that will do this speed selection for me? Based on flow rate or something?

John.G

Yes, you can Paul.

A few queries first.

What is the make/model of your present pump?,

What speed setting are you using, ie 1&2 or 2&3, or all 3, 1,2&3.

Where is the pump located in relation to the boiler, on the flow or return?.

Have you TRVs (thermostatic rad valves) installed on the rads.

How many rads?

Is your system sealed?.

See your using speed 2&3?.

paul-2008

https://www.boards.ie/discussion/comment/118431682#Comment_118431682

Thanks for the reply!!

Pump is a Grundfos Selectric UPS 25-50 130

Using speeds 2 & 3 currently, I found that speed 1 was too slow to bring heat into the rads.

Pump is located at the boiler, on the return side. Boiler is located in an attached garage and pipework running up through the attic and back down in the hotpress (in the centre of the house) and distributed from there.

TRV's on all rads yes

Number of Rads - Zone 1: 2 singles 3 doubles, Zone 2: 4 singles 3 doubles and then zone 3 is hot water cylinder

System is not sealed no

let me know if you need any more info! thanks

Kencollins

Hello!

I have a similar setup to yourself. Big two story house with three zones and TRVs on all the radiators.

I use a pump for each zone and have found the wilo modulating pumps excellent:

https://www.screwfix.ie/p/wilo-yonos-pico-25-1-6-130-glandless-circulating-pump-230v/6153x

You can see the pump power reducing as the TRV's start to shut down and restrict the water flow. Very quiet too, and not too expensive!

John.G

I have the exact same pump as Ken, one of its big advantages is that you can incrementally change its CP (constant pressure) & PP (proportional pressure) settings in 0.1M steps between 0.5M and 5.5M, most other smart pumps have only a number of fixed CP&PP settings which may not suit all situations.

Can you post the 3 pump power outputs in watts as there were at lest three different versions of this model.

Also make of TRvs as some of these are more prone to noisy operation, most are now bi directional which means they ca be fitted to either the rads flow or return, I have never had a problem with mine and have renewed the 10 over the past year with "EPH" which are excellent and relatively cheap.

paul-2008

https://www.boards.ie/discussion/comment/118432574#Comment_118432574

Thanks guys! looks like this may be the solution - does it sense when there is more zones open i.e flow reduces and then it ramps up pump speed?

Three outputs on the current pump are (1) 35W (2) 60W & (3) 85W

The TRV's are Heatmerchants own brand and are the Alpha TRV

John.G

Yes, it ramps up and down the speed as required based on flow requirements.

For example my pump will run at 22/24watts with all TRVs open and reduce to 14/16watts as TRVs/zones shut in.

Would think this pump should be a good choice.

You will receive two rubber gaskets with the pump, so use these in preference to any fiber washers, if you are also renewing the pump valves, get the gate valve type and not the ball valve type as the valve spindle O rings can leak eventually.

paul-2008

Great I think I will go with that so! Thanks a million for the advice lads

John.G

Very good, let us know how you get on when set up etc.

paul-2008

https://www.boards.ie/discussion/comment/118434463#Comment_118434463

Hi John G, I have this installed now but I'm struggling to see what m head I should set it at. Is there a way to check this? Or is it just a bit of guesswork?

John.G

OK Paul,only saw your post now.

There are three modes on that pump, PP (proportional pressure) CC (constant curve) and CP (constant pressue).

THe CC settings are in the middle, C1 , C2 and C3 which are like the traditional 3 speed pumps, C1 is ~ 2M, C2 (not a bad choice) is 4M and C3 is 6M (rarely needed).

Turning the selector knob anti clockwise (to the left of C1,C2&C3) gives the PP settings, every time you move it you will see the requested pressure (head) flashing, it will flash for a few seconds and then indicate the pump power W. Turning the knob clockwise (past C1,C2&C3) gives the CP settings, again, the same applies, it flashes the required pressure when you pause and then displays the power again.

I have mine set to PP 4.5M which gives a power consumption of ~ 22/24W with all TRVs open and ~ 14/16W with all throttled in.

Don't be put off by the UFH symbol as sometimes a CP setting can give the best results, depending on your system.

paul-2008

https://www.boards.ie/discussion/comment/118462890#Comment_118462890

Thanks, I played around with it last night for a while and have it set to 3.2M head and this seems to be sufficient so I will monitor for a few days and see! Thanks again for your help

John.G

That good to hear, presume its in CP mode.

What is the power output?.

I have mine at PP 4.5M which is ~ 3.4M/23W at full heating demand, so if your TRVs get noisy you could try this mode

Actually gives me 13.3LPM at a 3.7M head.