No Hot water !! Powermax 155

[Nickiejc]

Hello,

Powermax 155 boiler approx 6 yr old - We only get hot water for about a minute then turns cold was told it might need descaling but we have a a good flow of water. No one wants to touch the boiler themselves but I have been offered the following advice and don't no what to try !

Descale the system

Fit a waterwave on the boiler first to break down scale then fix to cold water pipe

Change blender valve

We also have a combi care unit under the sink that has never been changed by previous owners.

Any help much appreciated

 

[gazthepottertonengineer]

hi couple of things it could be firstly i woul change the blender or at least try and adjust it secondly make sure the thermostat for the heat store is working ok and then if still playing up check the plate h/exch !!

if the unit is under 5 years old i would call potterton as they will do a call out fee which includes all parts for £170 inc vat

 

[Nickiejc]

hi couple of things it could be firstly i woul change the blender or at least try and adjust it secondly make sure the thermostat for the heat store is working ok and then if still playing up check the plate h/exch !!

if the unit is under 5 years old i would call potterton as they will do a call out fee which includes all parts for £170 inc vat

Thanks for the advice, I have checked and the boiler is over the five years unfortunately !! Thanks for letting me know it is a Potterton boiler though as I didn't even know the manufacturer so I am going to try and get on to them. Would it be best to get someone to do the valve first before I get (s'cuse me for bein dumb) the 'magnetic thing' fitted ??

Thanks

 

[ollski]

Is the water hot in the cylinder (just have a quick feel under the insulation) or is it a problem with the boiler not firing up at all?

 

[Nickiejc]

Is the water hot in the cylinder (just have a quick feel under the insulation) or is it a problem with the boiler not firing up at all?

Yes the water is hot and it comes out of one tap downstairs scalding but all the others it only comes out boiling for about 2 mins ! Heating works fine aswell

 

[ollski]

Is the water hot in the cylinder (just have a quick feel under the insulation) or is it a problem with the boiler not firing up at all?

Yes the water is hot and it comes out of one tap downstairs scalding but all the others it only comes out boiling for about 2 mins ! Heating works fine aswell

Well if your temperature and flow rate are in line with the manufacturer's instructions from the scalding hot tap then there is no problem with the boiler. If it's because that tap has a low flow rate wheras all the others are at a higher flow rate then suspect a scaling problem.

 

[Nickiejc]

Is the water hot in the cylinder (just have a quick feel under the insulation) or is it a problem with the boiler not firing up at all?

Yes the water is hot and it comes out of one tap downstairs scalding but all the others it only comes out boiling for about 2 mins ! Heating works fine aswell

Well if your temperature and flow rate are in line with the manufacturer's instructions from the scalding hot tap then there is no problem with the boiler. If it's because that tap has a low flow rate wheras all the others are at a higher flow rate then suspect a scaling problem.

All the taps in the house flow fast. Someone said it was a scaling problem (and we are in a v.hard water area)and another said that it wasn't as the water runs fast and they think I should have the valve changed as it may only be letting a small amount of hot water through then just cold....also I have had three plumbers round now and nobody wants to do the job ?!?!?!

 

[ollski]

All the taps in the house flow fast. Someone said it was a scaling problem (and we are in a v.hard water area)and another said that it wasn't as the water runs fast and they think I should have the valve changed as it may only be letting a small amount of hot water through then just cold....also I have had three plumbers round now and nobody wants to do the job ?!?!?!

If one tap off the boiler works correctly at the flow rate and temperature rise it should be (you will need to measure them), then the boiler is fine. If it is the blending valve it will do it on all taps. powermaxes are horrible, I wouldn't work on them if i didn't have to.....one where it is worth getting the manufacturers in at a fixed fee.

 

[Nickiejc]

I am going to check them all when I get home and i will get in touch with the manufacturers aswell

Thank you for your time and advice

 

[gazthepottertonengineer]

potterton arent technically the manafacturers they just bought the company off Range
also i dont personally think it is a scale problem and fitting a hydroflow magnetic thing as you call it would take years to break the scale down

try looking at the flow switch simply check continuity across it when turning the hot tap on as this turns the pump on to circulate heating water around the plate h/exch

 

[Nickiejc]

I will try and check that tonight, soz if you have time could you tell me where i can find it

I did speak to Potterton today and they said they would come out for £235 which is fine but if it turns out to be scale they can't help...I wouldn't usually be this stressed but have already paid 2 nearly 3 call out fees

 

[gazthepottertonengineer]

follow the cold pipe in and its a black thing with 2 black wires coming off of it

im certain that this will be your problem and definately not scale by what you have told me

let me know how you get on

Gary

 

[Nickiejc]

Ok, I will have a check tonight and then reply

Thanks loads for you time

 

[Agile]

I would not have wished to pay "callout" fees for someone who then says he cannot fix it!

You and anyone else should ensure that you dont get anyone who will charge if they cannot diagnose the fault. Charging for diagnosing the fault is correct.

I have not fully understood your symptoms. The boiler does not know where the hot water is going to.

I only go to very few of your model but dont have much of a problem with those I see. Unfortunately its the kind of fault which I would expect is obvious but as its dynamic it requires checking various parameters at the point when the hot water delivery stops.

It could be that the storage is only partially getting heated. Or it could be that the boiler is not coming on to reheat it. No one has mentioned the diverter valve yet.

The potty engineers here are keeping rather quiet, perhaps because they find it a difficult unit. In reality apart from the blending unit its pretty similar to any other combi boiler. However, just that blending unit adds a further possibility of a fault.

Many in our trade if they cannot diagnose the fault say its scalled up and needs to be replaced. In reality almost all scaled up items can be cleaned but few want to bother. Oddly we do quite a few and quite often on behalf of other firms.

Tony Glazier

 

[ollski]

No one has mentioned the diverter valve yet.

Tony Glazier

In what way?, it's a twin pump thermal store system. Irrelevant really if one tap is working at the correct temperature rise and flow rate consistantly and the heating is working then nothing is wrong with the boiler.