valiant tubo max heat exchanger

[tootsie123]

i have been advised that the reason i only have central heating and no hot water is due to the heat exchanger being limescaled. will i be able to fix this problem with fernox or sentinel (if so which product) or do i really have to have the heat exchanger replaced. have only just paid for gas valve, cable and circuit board for second time in four years!

thanks

 

[gas4you]

Unfortunately these were not one of Vaillants finest I assume you mean the plate heat exchanger and not the main heat exchanger? The plate heat exchanger needs to be descaled with an approved descaler rather than the Sentinel you mention. These are just for the heating side cleansing and will not necessarily removed hardened limescale deposits.

 

[tootsie123]

wasnt told waether plate or main. are both of these repairable with the traeatment you suggest. also could you be more specific about what product i should buy or do i really need another plumber?

thanks

 

[Gasguru]

Who told you there was a limescale problem - did they actually inspect the boiler?

I assume the is a not a Turbomax but a Turbomax PLUS boiler.

Do you mean the boiler does not fire up when the hot tap is opened or that hot water performance is just poor.

These boilers suffer from diverter valves sticking - does the heating come on when using the hot water. Another common fault is the air pressure switch - this can also cause poor hot water performance since the boiler can cyle on and off.

 

[ChrisR]

What's the hot water flow rate through the boiler? Measure into say a 9litre bucket.
Should be at least 8 litres/minute

 

[tootsie123]

basically it has been a long running saga. it was put in under a grant system and has had gas valve fault twice in four years. the plumber did not check the system and then tennant said no hot water only heating. i fiddled with diagnostics and hot water did kick in then stopped working again. called out warm front pumber again and he said was due to heat exchange unit being damaged by lime scale but it has always had inhibitor through the system. the grant people are now saying it does not cover limescale and i am going to have to foot the bill! i do not trust the people from ideal boilers and fel they are just trying to wriggle out of the problem.

 

[gas4you]

i do not trust the people from ideal boilers and fel they are just trying to wriggle out of the problem.

Neither do I, but you were saying its a Vaillant. Is that why they can't fix it

You can descale plate heat exchangers with I believe citric acid, but whatever you use make sure it is suitable for use on metal. Fernox do a DS4 and a DS3, not certain off hand which one is for plate heat exchangers. No doubt someone will put me right on which one exactly to use. I've never got involved with descaling, I always just replace the plate heat exchanger.

 

[gas4you]

Now followede ChrisR's link on another post to Fernox site and it is the DS3 for descaling

 

[timmy74]

theres a DS12 as well im sure dunno how powerful this is like,, they all must be descalers DS=descale