No normal hot water flow

I recently bought a flat which is built in 2007 (by barret homes in Apsley) with a PulsaCoil A Class installed. I was told by previous owner the boiler is fine and I simply trust him and I think it is more likly to be fine considering the age of the property . But when I moved in , I found out there is a hot water problem.

1. I can not got normal flow of hot water both on off-peak and on-peak setting. The en-suite shower has a very tiny flow of the hot water.

2. In bath room tap and kitchen tap, I can rarely get any hot water flow although I can feel the tap is actually hot, just not enough water out of it.

3. For both on-peak, and off-peak. The temperature its-self is decent. Just the flow is tiny.

3. There is not any sign of failure or flashing led as indicated by the front panel

4. The top water tank is a bit low (not dry, just low than the label I think) . But after I top up after learn from the forum, there is no big difference.

I am a computer engineer but not good at this sort of thing since I never has any experience of the heat-storage stuff at all. By a guessing, there might be something wrong with the sensor control the flow of the water? For the shower, the 1st 30 seconds hot water seems good with normal flow, however, it immediately becomes cold and then becomes hot again, but with a very tiny flow.



Any help or comments?

Yao

A class.
Off peak / on peak are just heaters which heat the unit up.
Have you got a flow of water from the cold taps?
Is the hot flow the same on ALL hot water outlets?
Mike

yes, cold taps have normal flow of water (proper presure).

Not exactly the same but very close, the shower got a tiny hot water. Other place like bath/kitchen I hardly got any hot water at all. But the tap itself seems hot.

Yao

mike wrote:A class.
Off peak / on peak are just heaters which heat the unit up.
Have you got a flow of water from the cold taps?
Is the hot flow the same on ALL hot water outlets?
Mike

Well if the taps and shower are hot then hot water is getting there.
Look in your book / manual.
Take off cover, turn on tap and feel pipe coming from plate heat exchanger going to taps etc.
There may be a valve or similar which has been fitted outside the unit or inside which may not be fully on.
There is also a Y type in line strainer fitted on the cold supply into the unit.
This could be blocked.
But you need to read the manual.
And all the PC A class posts on here before attempting to look at your unit.
If not there is a list of advertisers on the home page on here.
Or Google up for a Gledhill repairer for your area.
The A class is not an easy unit for the non experienced person.
Mike

Thanks Mike, when you talking about blocked, you mean it needs to be physically changed or it needs to be turned on ?

mike wrote:Well if the taps and shower are hot then hot water is getting there.
Look in your book / manual.
Take off cover, turn on tap and feel pipe coming from plate heat exchanger going to taps etc.
There may be a valve or similar which has been fitted outside the unit or inside which may not be fully on.
There is also a Y type in line strainer fitted on the cold supply into the unit.
This could be blocked.
But you need to read the manual.
And all the PC A class posts on here before attempting to look at your unit.
If not there is a list of advertisers on the home page on here.
Or Google up for a Gledhill repairer for your area.
The A class is not an easy unit for the non experienced person.
Mike

A valve etc may be OFF if fitted.
A blockage would need to be cleared.
Units can be installed by people in various ways.
I only know the ones I see in my area.
If in doubt after looking at the posts and manual.
Post some pictures.
Mike

I opened the front, the board seems working normal. It is consistent with the manual page 24 and page 25. No sign of error code.
I took some pictures as well.

whole layout1:

whole layout2:

pipe1:
from the picture outside to inside, it is cold-water, cold-water, and the most inner side is hot-water

pipe2

The interesting thing is there is a gauge as shown in the picture. I do not know for sure what it is. But it should be in the incoming mains cold water.
There are 2 arms, one red, one black.
There is a valve you can control the the black one. I guess it is water pressure, Does it look normal? Actually I try to adjust a bit, it used to be less than 5, I make it a bit 6, it seems that the hot water slightly better. But I am not brave enough to make it even higher, worrying about it might cause a burst pipe or something. Anyone knows what it is, could that be down to the tiny hot water flow?
Can I simply adjust the pressure to maximum like 8 or 9?

mike wrote:A valve etc may be OFF if fitted.
A blockage would need to be cleared.
Units can be installed by people in various ways.
I only know the ones I see in my area.
If in doubt after looking at the posts and manual.
Post some pictures.
Mike

Is the flexi just hanging? It may be just means of filling the top tank.
The picture actually states on the component there is a filter.
It looks like a pressure reducing valve.
It appears to be.
Lever valve, double check valve, then pressure reducing valve.

yes, i use the flexi to top up the tank. That part is fine.


You mean make the number higher or lower?

[EDIT] yes, it is a filter, it is marked as "cartridge with filter"

It looks like a pressure reducing valve.
It appears to be.
Lever valve, double check valve, then pressure reducing valve.

I have a number of Pulsacoil A class in hard water arias, this is most likely the heat exchanger blocked from hard water. get a new exchanger and a kind of water treatment to extend the life span of your new exchanger and you will be ok.
regards Mario

Thanks mario. It sounds something beyond what I can do myself.

I am in Apsley, HP3 9 Area, do you have someone cover this area what will be the typical cost of this?

Thanks

Sorry for the delay, I also running a business ;-) ( and on site converting my vivaro in to a stealth camper)
The HP 39 area , there should be some to find at this forum. May from Newbury / north London or may ask Mike, he should be close( ?) to you. For me , this would be an about 95 miles trip to get to yours, ( I could but I have to charge a travel compensation for this, sorry)
Regards Mario

Could the DHW pump wrong? That supposed to supply the hot water pressure? I took the cover on Sunday 9：00 am, the LED of the DHW is on however I do not hear any sound from the pump.

Plus, there is a valve on top of the pump which seems to be adjustable, not sure whether that determines the hot water pressure.


BTW, it seems that we can not post the link to external picture any more?

Thanks