Can a diverter valve cause these symptoms

[scoobydo123]

Thanks for your time,

Thats what I thought when i noticed it was actually made by wilo

1-8 all fine just seems like it is not pumping with much force. Previous to the change the bolier was tripping out gradually getting worse(more resets 3 times a week) over time but was still heating the house. It then got to a stage where the weather had turned and CH was not required. decided this weekend it was time to invesigate and changed the pump. These stopped the gurgules and trips so was in the right direction!

 

[Agile]

I suggest that you do the bucket test ( see FAQ on this site ) at the pump to see if there is any blockage or restriction at the pump valves.

The Flowson is a very good pump as Kevin says! There is no advantage replacing it with a Grunfoss.

What would be more relevant is to measure the differential temperature across the boiler on CH only.

Tony

 

[scoobydo123]

Tony

with the bucket test, when it says remove the pump head to test, what is meant? When I replaced the myson, I put new isolator gate valves either side so all should be free to move and not blocked at the valve end. Is the pump head just a case of undoing the 2 allen bolts and removing the impeller or do I remove the whole pump? I do need to change the flowson as the gland supplied was wrong so the electrical connection cover will not fit properly and also the sprung loaded connections do not work properly.

Also possibly worth mentioning is that if all rads are shutdown and bought back one at a time they are hot.

Cheers

 

[scoobydo123]

My temperature probe is at work so cannot measure differential. However it is nowhere near 11c (much cooler). Also I have just left all upstairs radiators on and just one downstairs and the downstairs does not get hot at all.

Thanks

 

[gas_man_gaz]

id check the cold feed isn't partially blocked. could do this be removing the pump and opening the top pump valve into a bucket or rubble bag. make sure ya get a good flow out of it and ya hear the f+e tank filling up.

 

[D_Hailsham]

The Flowson is a very good pump as Kevin says! There is no advantage replacing it with a Grunfoss.

Apart from the fact the the Flowson is has a D Energy Rating and the Selectric 15/50 is B rated. The Grundfos Alpha as A rated.

My temperature probe is at work so cannot measure differential. However it is nowhere near 11c (much cooler).

How can a differential be cooler? It can only be greater or less than 11°C. If the differential is too great, the pump speed is too low.

The Flowson has 5 Metre head while the CP53 is nearly 6 metres.

Here is my Balancing Procedure

 

[scoobydo123]

I meant my return pipe is much cooler than my flow and nothing like what it should be. Will have another go at balancing. Interesting that the cp53 is almost 6m could this be the problem? Will be having a go at all the suggestions given over the weekend but want to go for the easy ones first. Previously the system was not balanced properly all lockshields fully open and it performed ok but obviously no ideal.

*****Edit to add some more detail*****

Brief update for this morning. Turned all upstairs rads off and all downstairs on and the whole downstairs works. However, no matter if up or down is all open I am not getting the correct differential between flow and return. If DHW is only selected then I the return comes up to temperature (measured by hand only at the top of the boiler). Cannot measure as my probe is in work but promise to bring it home tonight.

Thanks for the help

 

[scoobydo123]

Managed to get flow to all rads using D_Hailsham balance guide (thanks). Have been out allday and left the heating on circulation (low boiler temp) to try and circulate the x400. Here are the measurements that I am getting when boiler is set to the "normal" operating temperature.

Flow=58 Return=46, I measured this at the top of the boiler where the flow and return exit the boiler. However it takes an age for the return to get to this temperature as the bolier seems to reach 58 then shut down whilst the return has hardly any heat in it. Just timed the sequence after letting the system cool down to luke warm it seems to run for 1min 8 seconds then shut down for 55 seconds. I assume this is not correct as the ignition circuit is taking a hammering doing it this way.

I have read on the forums about blockages where the 15mm pipe from the f&e tank is a likely place for blockages where it T's into the boiler and continues towards the pump, are there any tests for this before I go chopping pipes. Obviously the x400 is still in the system and has only been circulating around all the rads at once for today would it be likely to clear any blockages or is it too serious. Have also got 3 bottles of x800 but no powerflush machine that I could introduce.

On the hotwater side I have just changed the program from DHW&CH to DHW only and within 2 seconds the return pipe came up to flow temp (actually felt hotter) and the boiler was not even on. Does this give any extra clues? Just timed this and it is on for 40seconds then off for 4 minutes. Perhaps another test I could carry out is from cold switch to DHW and see if the boiler will stay heating the water without this cycling.

Thanks again

 

[D_Hailsham]

Here are the measurements that I am getting when boiler is set to the "normal" operating temperature.

1 What do you mean by "normal" temperature?

2 What number do you normally have the boiler thermostat set to?

3 Do you have a room stat?

4 The Prima 60F can be range rated; the setting should be given on the data plate. What is it set to?

 

[scoobydo123]

All sorted,

Changed the flowson pump, new from B & Poo last Sunday to a Grundfos purchased from Ebay and everything is running fine. Boiler no longer cuts reaches boiler Stat temp in 1 minute then off again. Taking the flowson back for a refund. In answer to the questions

1. Normal as in what I set the boiler thermostat to 3 and half
2. 3 and half
3. Yes to the roomstat
4. Not sure where the data plate is.

So moral of the story is dont trust a new part as working. Altough the new one was better than my old one 13 years plus it still was not working 100%.

Last question I hope, am I correct to assume that whilst the x400 is circulating I should open all lockshields?

 

[D_Hailsham]

In answer to the questions

1. Normal as in what I set the boiler thermostat to 3 and half
2. 3 and half
3. Yes to the roomstat
4. Not sure where the data plate is.

If you have a room stat, there is no need to set the boiler stat so low. Set it to max, so the flow and return temps are higher, and leave it to the room stat to turn the boiler on and off.

You may have to remove the boiler casing to see the data plate.

Last question I hope, am I correct to assume that whilst the x400 is circulating I should open all lockshields?

Yes, it's what Sentinel recommend.

Leave the X400 in for 4 weeks then drain and flush with cold water until it runs clear. Don't forget to add some X100 inhibitor when you are half way through the final fill and, if you are in a hard water area, also add some X200.

Then rebalance the system!

 

[scoobydo123]

Over the years have been gradually reducing boiler stat due to nuisance tripping (was never at max from install). However I can now set to MAX and i have not tripped. Unable to find a data label apart from the one I have attached. Will follow the 4 weeks and x100

Untitled

• scoobydo123
• 17 May 2009
• 1

 

[D_Hailsham]

Unable to find a data label apart from the one I have attached.[/net]

That's the label I was talking about.

The top line is probably labelled Heat Iin or similar; the next line Heat Out and the third line Burner Pressure. There are three figures given for each line - these are the power settings available - the installer adjusts the burner pressure to the figure quoted. In theory there should be a label with an arrow pointing down at the top of one of the columns to show the boiler setting. As I can't see one, I would guess that it is set to max output - how it comes from the factory.