Potterton Performa28i problems

[tukky142]

Hi,

I have a problem with a performa 28i. The boiler has a problem where the hot water light flashes for hours even though no hot water taps are on. The boiler is set to pre heat but it shouldnt be pre heating for hours. The rads were slightly warm as if some water was getting through to the rads. Could it be a problem with the hot water sensor? Or could it be s sticking hotwater/ch valve?
Is there some tests I could perform to check each out?

 

[cross thread]

any dripping hot taps?.try turning off flow valves to stop it passing to the rads , if it now satisfies pre heat may be faulty diverter valve

 

[tukky142]

No hot taps dripping. The problem is that this isnt happening everyday! Its happend two or three times now. If I removethe diverter is there something that stands out to tell me thats the problem or is it just a case of changing the diverter

 

[Baxi-Remeha]

how hot is the pre heat getting....

could be a number of things. such as divertor valve letting by into ch(likly), so the pre heat cant get to temp. where abouts in warwickshire are you???

 

[tukky142]

Near Bidford on Avon. The preheat is only set to first notch if its any lower the shower takes ages to warm up in the morning. I have had another problem which may be linked and has has never been sorted - at night when the CH is off and the boiler is set to pre heat during the night the boiler starts to make a kettling sound as if the store of water is boiling up - I never notice this in the day. Could this be linked to hot water sensor or diverter?

 

[Agile]

Whever happenned to that Moose head opposite the antique shop?

Answer that and I will tell you whats wrong with your boiler!

Tony

 

[tukky142]

Do you mean the antique shop by the frog and bullrush pub?- As for moose head - how longa go you talking? We only been here 2.5 yrs

 

[Agile]

Right, a newcommer then! I will have to let you off then!

The Moose head is/was in the Bidford auction rooms almost beside the pub ( off licence in between ) and opposite Bidford Antiques.

It sounds as if the DHW flow switch gland is leaking and making the microswitch conduct which causes the boiler to bekieve there is a demand for DHW.

Cure is to replace the gland and perhaps the microswitch although it might be recoverable by drying it out.

The operating pin must be carefully cleaned to ensure there is no deposit at all on it.

Gland leaks due to dirt in the water so unless the water is treated it may reoccur.

Tony Glazier

 

[tukky142]

I think you have Bideford mixed up with Bidford!

My boliers latest symptoms are - woke up to a boiling hit house this morning. Went to boiler and the hotwater neon was flashing but the rads were boiling hot and there was no demand for heating.
It appears that the boiler 3 port valve is sticking or the valve head is not working. - Is there a test I can do to prove what is wrong?

 

[Agile]

No, I just spelt it wrong and I have corrected it now! I dont do boiler repairs in Devon! Nothing further west than Weymouth. Ask any established locals about the moose head!

So now your boiler in Bidford, it still sounds as if the hot water flow switch is getting wet from a leaking gland and causing the boiler to think there is a demand for hot water and consequently heat the radiators instead !

Try to identify this switch and you will probably see the droplets of water on it !!!

You have one of the few Fish and Chips shops that I would consider buying from if I was starving!

I did a boiler repair for someone down the other end of Bidford in the tiny new houses last summer!

Tony

 

[tukky142]

Oh ok - I will ask my next door neighbour he has been around here for many years so should know the moose head - its just that I have had someone else get Bideford and bidford mixed up.

As for the boiler - if I find droplets of water on the switch what is the fix. How come the rads got warm this time - isnt there a problem with the diverter valve then as well? I have replaced the HW diaphram in the past when the boiler would not switch onto hot water when I opened a Tap - it had two holes in it.

 

[Agile]

The fix is to replace the gland after cleaning every speck of dirt deposit off the pin

Then to ideally replace the switch but it may recover if its dried with a hairdryer for about 30 minutes.

Tony

 

[tukky142]

I have just opened up the boiler and checked the microswitch - I cannot find any traces of water droplets or crustydeposits. I even took the lid of the black box but still not deposits anywhere.
When you say replace gland do you mean on the differential or microswitch?

But.... The sensing pipe that connects underneath the DHW differential valve has been leaking - there wasnt water present tonight but ther was lots of crustydeposits both on the connection and on the floor of the boiler - could this be an issue?
There are also the same deposits on the DHWtemperature sensor - could the sensor be on the blink or scaled up?

 

[Agile]

Did you notice if the DHW flow switch pin is retracting sharply when the DHW demand ceases?

It could be that the diverter or hydraulic unit is sticking.

I can only suggest the most likely cause.

If the pin is retracting quickly can you remove the switch an do a resistance test across the NO contacts?

Tony

 

[tukky142]

To be honest I couldnt really say -I presume I have to remove the microswitch to see this?

Today when CH is called for the Hotwater icon comes on but the heat is going to the heating flow pipe.

I wanted to check the CH pressure diaphram so I isolated the boiler by turning off feed and return taps and drained the primary Circuit (or I thought I had) by opening the drain tap. Once the water stopped I then undid the four screws to the CH pressure diff. valve cover but was met with loads of water continusly running. Am I doing something wrong is there another way to drain the primary circuit? Is this all partof the problem with the diverter valve sticking?

What have I got to change is it the diverter operating head or is it the CH pressure differential diaphram that needs changing. Shall I justget one of each?

What should the resistance test say? what is the spec - Do you do this by removing the lid from the microswitch and connecting across the terminals.