Are my Grundfos pumps configured correctly? Old one pipe system, with 16 radiators powered by a 48kwh regular boiler.My bills are £800 a month.Help.

[Johntheo5]

Take a few readings off that LLH sometime, if only for interest.

 

[JonnyH12]

OK, I will try and make it a bit easier, these tests will help tell if the pump(s) are on the correct settings.
Do this test only first, CH only on. and post back your readings.

1 should be the same as the boiler flow temperature, around 65C?
2 should be fairly low ~ 35 to 40C
3 should be similar to 1 but may be lower
4 should also be lowish.

Okay.

1 is 60c.
2 is 34c
3 is 44c
4 is 36c

 

[Johntheo5]

You are only getting 30% rad output at that 44/36 differential which maybe causing g the boiler to cycle unnecessarily, you should/might decrease the CH pump setting, maybe go one speed lower.

 

[Johntheo5]

You are only getting 30% rad output at that 44/36 differential which maybe causing g the boiler to cycle unnecessarily, you should/might decrease the CH pump setting, maybe go one speed lower.

Ideally, except running flat out, the primary and secondary flow rates should be more or less equal

 

[Johntheo5]

As your HW flowtemp is also probably ~ 44C ish and if the cylinder stat is set to 60C then the boiler will never cut out on HW only if its getting its run signal from the motorised valve.

 

[JonnyH12]

You are only getting 30% rad output at that 44/36 differential which maybe causing g the boiler to cycle unnecessarily, you should/might decrease the CH pump setting, maybe go one speed lower.

I did turn the pump down, but I noticed the water did not seem to be flowing into some of the radiators very well. The TRV valve side and top of the rad was hot, but the bottom and return lockshield was cool if not cold. Picture of the radiator in question attached.

The actual pipe around the house stays hot to the touch.

Ideally, what temps should I be seeing on each number you marked?

Your point about hot water is a really good one. I checked that and it's taking a long time to get to 60c, about 90 minutes, and that's only if the heating was not on att the same time.

Does that suggest the pumps are set too high, low or that my boiler temp needs turning up?

 

[Johntheo5]

Ideally 1&3 should be equal and 2&4 fairly close.
Can you post the exact models and present settings of the 3 pumps.

 

[Johntheo5]

Ideally 1&3 should be equal and 2&4 fairly close.
Can you post the exact models and present settings of the 3 pumps.

If the pumps are all UPS3 then check settings of all 3, increase the primary (boiler) side by one if available and recheck temps 1&2 and 3&4.
Yon try setting the HW pump one lower and then check 1&2 and 5&6 with HW only on.

 

[JonnyH12]

Ideally 1&3 should be equal and 2&4 fairly close.
Can you post the exact models and present settings of the 3 pumps.

The pump is Grundfos UPS3.

I read online that there should be a 20c differential between the output valve and the return valve, so was measuring the first pump and the magnetic filter. I was getting 68c and 55c earlier using Constant Pressure mode 1 on the CH return pump, and constant speed 2 on the pump coming off the boiler.

However, some of the radiators do not seem to be getting water in very well at all - the top of the rad heats up but doesnt seem to be being pushed out of the return lockshield, meaning the middle and bottom of the rad stays cool.

 

[BlueLoo]

At some point, you are really only going to gain so much margin out of improving the system efficiency.

Ultimately, baring an absolutely ridiculously bad system, you need to look at how much heat you are needing to input into the space and where/when you need to do it.

You likely need a three pronged approach:

1) update the building
2) update the boiler and infrastructure
3) update the controls.

Anything else is likely small beans in comparison.

Times have changed. Listed building under occupation need to be habitable. I would have a company come in, prepare a remediation plan which is sympathetic as can be to the listed status and get speaking to the local planning office.

You have an ace here, any building that is so bad it is uninhabitable quickly becomes derelict.
It is a strong point to argue.

Oh, and don't assume plumbers or builders know what they are doing.
Do due diligence on any tradesmen before employing them.

 

[JonnyH12]

At some point, you are really only going to gain so much margin out of improving the system efficiency.

Ultimately, baring an absolutely ridiculously bad system, you need to look at how much heat you are needing to input into the space and where/when you need to do it.

You likely need a three pronged approach:

1) update the building
2) update the boiler and infrastructure
3) update the controls.

Anything else is likely small beans in comparison.

Times have changed. Listed building under occupation need to be habitable. I would have a company come in, prepare a remediation plan which is sympathetic as can be to the listed status and get speaking to the local planning office.

You have an ace here, any building that is so bad it is inhabitable quickly becomes derelict.
It is a strong point to argue.

Oh, and don't assume plumbers or builders know what they are doing.
Do due diligence on any tradesmen before employing them.

Thank you, you make a lot of sense. What sort of person or company would you look for to come in and help?

 

[Johntheo5]

The pump is Grundfos UPS3.

I read online that there should be a 20c differential between the output valve and the return valve, so was measuring the first pump and the magnetic filter. I was getting 68c and 55c earlier using Constant Pressure mode 1 on the CH return pump, and constant speed 2 on the pump coming off the boiler.

However, some of the radiators do not seem to be getting water in very well at all - the top of the rad heats up but doesnt seem to be being pushed out of the return lockshield, meaning the middle and bottom of the rad stays cool.

CP1 at 3M is probably too low for the CH side, CP2 at 4.5M may be sufficient or CC2 at 5.2M, CC3 at 6.3M should certainly be sufficient, problem then may be that even with the (boiler) primary pump also set to CC3 is that less water may circulate through the boiler and more through the rads causing some cold return water to mix with the hot water causing reduced rad flow temperatures. Ideally the primary and secondary flows should be equal like a system with no LLH or if the primary side flow is slightly higher than the secondary then the secondary flow temp will be the same as the boiler flow temp but the boiler return temp will be somewhat higher than the rads return temperature.
Suggest trying the rad pump at CP2 (4.5M) and the boiler side pump at CC3, (6.3M).