Old system in new house poor hot water temp

[scoobydo123]

Hi, completed on a house that has a Potterton kingfisher 2 free standing boiler with cylinder in cupboard above and pump external to boiler and roomstat in hall. Heating seems ok, DHW not that hot. I have had look around and cannot see a diverter valve but can see the attached on the return from the cylinder. Also attached is a picture of the timer which I believe is in 10 way mode although I can set CH independantly from DHW either via boost button or moving the sliders in a certain order.

Can you tell me what the valve is on the cylinder? Does this regulate the temperature of the cylinder, if so how do I adjust? If no separate control is available what happens when roomstat is satisfied will the DHW still work and what happens in the summer with such an arrangement?

Will put something new in but money is very tight at the moment and would like to rent out to family member whilst they wait for the person they are buying from to find a house.

Untitled

• scoobydo123
• 27 Dec 2010
• 1

Untitled

• scoobydo123
• 27 Dec 2010
• 1

 

[Hugh Jaleak]

How many pipes are there from the boiler? Valve looks to me like an auto bypass valve, not sure why its been fitted there or even if it'll work installed like that.

 

[scoobydo123]

looked like 4 when I had a poke around

Cheers

 

[picasso]

I think its a cytrol valve, its probably failed if your hot water isint hot enough, have you checked that the expansion tank in the loft has water in it ?

 

[scoobydo123]

Sorry haven't checked the F&E tank but will check it out tomorrow. How do you adjust the cytrol valves? Does it lock into position or should it freely turn. The 28mm flow to the cylinder seems to get hot but the return has very little heat at all. Also on the CH circuit there appears to be a compression ballofix type fitting is this for summer use to stop the rads getting hot?

tks

 

[numpty1]

you can adjust them,but it will leak unscrew the blue cap and wind the spindle anti clockwise about half a turn if you feel lucky ,normally fitted to gravity hot water,your rwb clock is set for gravity hw[10]fully pumped is 16

 

[scoobydo123]

Not sure if I have any other option than to give the valve a tweak. House has been empty for 3 years but apparently heating has been left on tick over, previous occupant was perhaps only using electric shower so perhaps someone turned it down as no baths required. If it does leak are we talking just like what happens with old lockshields where they leak up the spindle?


Or could it be an airlock in the cylinder pipework? Is there any significance in the appearance of 2 sets of flow and return from the boiler or is this normal for a gravity system.


tks

 

[numpty1]

yes just like a lockshield,it may weep along the spindle or spray out if you are really unlucky or heavy handed two flows two returns.gravity circs are normally 28mm1 inch but 3/4 22mm has been known to work.it may just be air in the coil if you are lucky.not for the feint hearted you could let the boiler bounce by letting it boil once you are certain it is full of water.

 

[scoobydo123]

Ok, if it is an airlock and the system appears to be full of water all radiators are hot and the one radiator that I did need to bleed (bathroom one) water quality looked clear to make the boiler "boil" is it a case of turning to max and removing the thermostat bulb from the HE?

thanks for all your help

 

[Hugh Jaleak]

Check F&E tank has water in it, drain some off from a rad and ascertain the system refills as it should and cold feed isnt blocked. If there's a vent coming from the top 'T' where the primary flow goes into the cylinder, (connection above the valve in the pic) then it shouldn't be airlocked. Either valve is jammed shut or the system is full of crud.

I'd remove valve and replace with pipework. Whilst its apart flush coil through with a hose to check its clear.

 

[numpty1]

oh yes thats it

 

[scoobydo123]

Ok will try all the suggestions although it looks quite tight to change cytrol valve for pipe. Will get some x800 and give that a go. As i suspect it is more a cylinder issue than CH can I set the timer for CH&DHW but turn the roomstat down should I still get the HW circuit running on this type of design as was thinking of adding the x800 and concentrating on cylinder first?


Ps how long should I let it boil for


help really appreciated

 

[Hugh Jaleak]

Cylinder to boiler primaries circulate via gravity. Switch hot water on by itself, once the water in the boiler hits the right temperature its surprising how quickly it gets up to the cylinder! (Assuming there's no blockage anyway...) Roomstat simply switches the pump on to circulate water around the rads when roomstat gives call for heat.

X800 is for powerflushing, X400 would be better for your application. X400 can be left in for a few weeks without causing too many problems. http://www.sentinel-solutions.net/product/listing/central-heating/liquids/

If the X400 doesnt work, then I'd look to cut pipework and remove valve. Fit a new Female iron to compression fitting to the cylinder tapping, and rejoin to existing return lower down. Personally, I'd be wary of tricking the boiler into boiling the system!

 

[numpty1]

Cylinder to boiler primaries circulate via gravity. Switch hot water on by itself, once the water in the boiler hits the right temperature its surprising how quickly it gets up to the cylinder! (Assuming there's no blockage anyway...) Roomstat simply switches the pump on to circulate water around the rads when roomstat gives call for heat.

X800 is for powerflushing, X400 would be better for your application. X400 can be left in for a few weeks without causing too many problems. http://www.sentinel-solutions.net/product/listing/central-heating/liquids/

If the X400 doesnt work, then I'd look to cut pipework and remove valve. Fit a new Female iron to compression fitting to the cylinder tapping, and rejoin to existing return lower down. Personally, I'd be wary of tricking the boiler into boiling the system!

not much experience of gravity sys then?

 

[scoobydo123]

Solved,

Took cupboard apart that housed the cylinder to get a better look and found a bleed nipple sweated onto a tee joint on the flow to the boiler. Opened and got some air out felt the return and this ramped up to a decent temp very quickly.

Would you still stick some x800 in or is it a case of if it aint broke dont fix it? Didnt check if it was air or hydrogen so will need to stick some x100 in but should i try a desludge first?

thanks