biasi Garda Plus M110.32SM/E-Cold/hot water but c.h. fine

[zahra]

Hi

I am having problems with my combi boiler, the boiler is now 2 years old and usually no probs but yesterday I increased the water pressure and increased the DHW temp to from4 to 5 and noticed the water got really hot but then got really cold and then the boiler locked out so I reset it but since then the water goes from hot to cold to hot to cold. The temp gauge goes from 30 deg from turning on the tap to 70 to 80 to 90 then water gets really hot and temp goes down water gets really cold. Today it passes 70 deg and starts making a sound and cuts off and water goes cold.

Please can some one advise

Thank you

 

[Agile]

Unfortunately for you, it seems the installer did not properly clean the radiators by power flushing and the primary side of the secondary heat exchanger has now become blocked.

Being in Berkshire there might also be some scaling of the secondary side of the secondary heat exchanger. That would not normally occur but can be provoked by a dripping hot tap etc.

Cure is cleaning or replacement of the secondary heat exchanger!

Tony Glazier

 

[zahra]

Thanks Tony

could this still happen if the rads were all new? We installed all new pipes, conections, rads and the boiler at the same time?

Do you know if this is a costly to flush the system and replace the heat exchanger?

 

[Agile]

Some of the worst cases I have seen have been on new installations which have not been properly treated.

However, I do not know if your problem is as a result of dirt or lime scaling.

Only last week in Reading I encountered the first pure lime scaled secondary heat exchanger I have ever seen.

I am working on cleaning the old HE and that is taking a very long time as it has to be done slowly as it effervesces so energetically.

The exact reasons for depositing lime scale were not totally clear but the user was not operating the boiler is the advised way which would not be helping. The hot tap was also dripping and I suspect that was the main cause although he said it had only just started dripping!

Power flushing is about £350 and just replacing the secondary heat exchanger is about £146.

Tony Glazier

 

[zahra]

Hi Tony

I spoke to a Biasi engineer today who said the fault is the heat exchanger being blocked just like you mentioned could be the cause.

He said I will need to replace the heat exchanger for the DHW and fit a Scale master reducer on the water and a magna clean filer for the CH. He said all in all it could cost 335 inc of labour

He also said if I get the parts then I just pay 70 pounds labour, but I don't know where to get these parts from.

Do you think this is reasonable as I don't want to pay all this and find out I paid over the current rate?

thanx in advance
Zahra

 

[fazedup71]

a magna clean is a good thing to fit but is not always the magic cure to a central heating problems, whilst it will certainly help, if your system is in such as bad way at an early age i would still say have a power flush, plus you need to maintaine the magna clean on a regular basis, maybe the installer just filled the system first time and left all that nasty dirty water full of flux etc inside your system. You probably don't have any inhibitor in your system either, while you can get the parts yourself to save a few pennies it might be best to get the RGI to get the parts you need, your heat exchanger can be cleaned instead of replacement but it depends on what your installer likes to do, I think 80-90 for job depending on your area

 

[Agile]

Hi Tony

I spoke to a Biasi engineer today who said the fault is the heat exchanger being blocked just like you mentioned could be the cause.

thanx in advance
Zahra

I think I should withdraw from this discussion as you clearly think that he knows a lot more about boilers than I do !!!

What was his name in case I ever need advice on repairing boilers?

Tony

 

[zahra]

Hi Tony

Sorry if I caused offence I have never used these forums and I am def not technically minded as my husband is contantly reminding me of

What I was trying to but failed to say was Thank you to you as without even seeing the boiler and from my brief description of what was wrong with my boiler you were able to tell me straight away that it is the heat exchanger

That is what I was trying to say