Heatline vizo c28 DHW noise

[davyz]

Hi guys, Please can any members offer advice on the following.

I have a heatline c28 boiler which has operated with no problems whatsoever for approx 7 years. It was retrofitted to an existing system and was mains flushed when installed and sentinel inhibitor was added. It is likely with the odd leak now and again over the years on valves that the inhibitor has been weakened/diluted. it has given me excellent service till now.

I am aware that it is a very cheap boiler/system, but in mitigation it is a very small house with 5 rads.

Recently approx 6 weeks ago I went to turn a rad down and the valve broke so the system was emptied and the valve fixed and inhibitor re-introduced, I also added leak sealer. both here of the cheaper b + q variety.

The heating ran fine as before for approx 2 weeks then we went away for 5 weeks with the system not been used and came back on the 14th Jan. The heating and DHW ran fine all the next day, but the next day when hot water was drawn from the tap the most horrendous whine and vibration started, it carried on for approx 30 seconds then subsides and goes but sometimes does it again if the tap is opened near max

The symptoms are. if you open the tap gradually and don't open it full chat (about half) then the boiler vibrates and makes the noise but only for about 2 seconds then is fine. Almost like blowing off, I have noticed a plume from the flue for that second then normal

The hot water is brilliant and the flow same as alway,s no getting hot then cold etc. (I have turned the temp down a bit though) and the heating is brilliant. Set on the "e" setting.

The noise is with the boiler not pipes.

I have ran the hot water tap with the electric cut and the flow is the same but no noise.

I have ran the hot water tap with the CH off and the noise is the same and still great flowing hot water.

Checked down the flue from the outside and it does not seem blocked.

I think the fan is running OK

I am competent with being able to mains flush the system rad at a time then boiler but would like to put in some sentinel x800 or similar product and run it in the system. Please can a member tell me if the boiler has an aluminium heat exchanger as the product says 2 hours max. I would like to leave it in all day if possible to give everything a really good clean as some threads suggest. How much time would be recommended?

Any advice is greatly appreciated.

Thank you.

Dave.

 

[tackleburger]

Sounds like the diverter valve is problematic. Not fully up to speed on the Vizo although they are known to be better value than most at the price. If you heating is off and you tern the tap does it still do it every time or just once a day??

 

[tackleburger]

I think it has a copper exchanger but I doubt sludge is the problem. Suggest you get a GSR plumber out to look at it.

 

[jam1979]

did u bleed your pump when you filled your system back up could be air trapped in the impellar

 

[davyz]

Thanks so much for the very prompt responses.

I will get an engineer if I need to do any more that bleeding the pump or giving the system a flush with something.

It does it almost every time with the CH on or off but not as much as when it first started, however we might just be being careful when turning the tap on rather than turning it up without thinking.

It does say to bleed the pump when refilling but as I have drained and refilled the system once before with no issue or bleeding the pump, I did'nt give it a second thought so I will make sure I do that very thing tonight or tomorrow (as may be working late) before anything else and report back.

The boiler was fine for two weeks after I last filled the system and did only start playing up a day after our return when we started the heating to warm the house backup after it had been empty. I wondered if I had dislodged some debris with the new inhibitor or when I emptied the system or perhaps the sludge remover. I did notice when I bled a tiny bit of water out last night to check the water colour the bleed tap blocked for a second with some glob like looked like whitish melted fat like substance before the water carryied on flowing into the container. I thought it was the leak sealer coming out hence me thinking it needs a clean.

I forgot to say the pressure is just over 1 bar when cold and at 1.5 when running, it stays constant at this until it goes off.


I would like to still clean the system out as the water is pretty blackish I noticed when bleeding the rads recently so could i Put in some strong cleanser? once the issue is sorted or as part of the fix? how long could I leave it in?

Thanks again.

Dave.

 

[davyz]

Hi guys, I took the outer front off the boiler and bled the pump. Am I right in thinking all I had to do is note the position of the screw then undo it anti-clockwise until water trickled out for a short while. I tightened it back up to what it was topped it up and ran the system. I then repeated the process. I did not notice any air come out. However the noise is now there when the central heating is ran and it sounds like a plane going over, temp is still fine but we wont be running it up with that noise.

Can anything else be suggested.
I live in Hull if anyone is local.

Thanks again.

 

[Unregistered]

Dave,

My boiler is doing the exact same as yours! Same model. Did you ever get to the bottom of it?

KR
Matt

 

[lame plumber]

you'll never know unless you register!

 

[Dotty]

Thread closed.