Hot Water not lasting as long and radiators taking longer to heat up

[fixitflav]

So should I be able to just unscrew the 4 bolts and check to see if it is full of muck?

I believe so.

Will I need to turn all the electrics etc off

Definitely turn the power off, close the pump valves, and be ready to catch/mop up the water which falls out.

 

[Johntheo5]

If/when you check/clean out the pump check those pump readings again, if the pump impeller/pump ports are clean then you may have a pump electronics problem.
I saw when I looked at it on my laptop that you have a Grundfos Alpha 2.
16W on fixed speed2 = 3.67LPM, 0.22m3/hr @ a 3.0M head, very poor, would have expected ~ 8 to 10LPM. IF it actually is only 3.67LPM then fixed speed 3 should give a flowrate of 5.33LPM, (0.32m3/hr) @ a 6.1M head and 38W but its showing 49W which should equate to a flowrate of, at least 10.83LPM, (0.65m3/hr), so something clearly wrong.
Would suggest, sometime, changing to CP (constant pressure) 2, which at @ 4.5M head should give a flowrate of 4.5LPM, (0.27m3/hr) and ~ 26W IF the data from fixed speed 2 is accurate. Of course, 4.5LPM at a 4.5M head is hopeless, if true, would expect at least 13.5/15LPM.

RE the mid position valve, if HW only selected, then you should feel a fairly stiff resistance immediately on pulling it across to mid position, it should then return to its original position on letting it go.

If you want to see if its operating fairly normally in all three positions, select pump mode PP (proportional pressure) 2, you should then see the (power) watts changing on the three valve positions, again assumes pump is working properly.

 

[Adam Bill]

If/when you check/clean out the pump check those pump readings again, if the pump impeller/pump ports are clean then you may have a pump electronics problem.
I saw when I looked at it on my laptop that you have a Grundfos Alpha 2.
16W on fixed speed2 = 3.67LPM, 0.22m3/hr @ a 3.0M head, very poor, would have expected ~ 8 to 10LPM. IF it actually is only 3.67LPM then fixed speed 3 should give a flowrate of 5.33LPM, (0.32m3/hr) @ a 6.1M head and 38W but its showing 49W which should equate to a flowrate of, at least 10.83LPM, (0.65m3/hr), so something clearly wrong.
Would suggest, sometime, changing to CP (constant pressure) 2, which at @ 4.5M head should give a flowrate of 4.5LPM, (0.27m3/hr) and ~ 26W IF the data from fixed speed 2 is accurate. Of course, 4.5LPM at a 4.5M head is hopeless, if true, would expect at least 13.5/15LPM.

RE the mid position valve, if HW only selected, then you should feel a fairly stiff resistance immediately on pulling it across to mid position, it should then return to its original position on letting it go.

If you want to see if its operating fairly normally in all three positions, select pump mode PP (proportional pressure) 2, you should then see the (power) watts changing on the three valve positions, again assumes pump is working properly.

So I have changed the pump to constant pressure 2 and am getting a reading of 29W and on PP 2 I am getting a reading of 13W.

I'm a bit out of my depth here, which mode do you think would be best based on this?

On the mid position valve there is resistance but it does not return to its original position.

 

[Johntheo5]

So I have changed the pump to constant pressure 2 and am getting a reading of 29W and on PP 2 I am getting a reading of 13W.

I'm a bit out of my depth here, which mode do you think would be best based on this?

On the mid position valve there is resistance but it does not return to its original position.

I'm afraid you have a pump problem, either due to sludge/obstruction in the pump impeller vanes and pump ports etc. or else the pump has a problem electronically. Based on your CP2 data of 29W, 8.33LPM, 4.5M should result in a PP2 flowrate of 4.96LPM at 1.6M head but its showing 13W which equals a flowrate of 11.6LPM at a (lower) 2.0M head, impossible.

Have you removed the pump head?, if not, then you should, clean the pump , reinstall the head and take a few readings again, say CP2 and PP2 again, for a start.

Before considering doing this, if not done so allready, you might leave it on PP2, take readings with HW only requested, HW&CH requested and CH only requested, you should see a slight change in the power levels even with a (IF) defective pump, at least it should show that the valve is operating correctly. I would suggest then returning it to CP2 until you decide what to do.

Below are actual readings that someone sent me from a newly installed Alpha 2, for reference.