Amicus 6kw Instant Water Heater "Nightmare"

[chirpychippy]

Good evening all,

I get the sense that I am missing something after installing this water heater and it not working.

The electrical connection was carried out by qualified sparks using 6mm, straight from the consumer unit so this isn't the problem.

I did all the water connections and this is what I done:-

1st attempt.
Turned off the main and put a handled lever valve on the main under the kitchen sink I then ran a bit of copper pipe to a tee, tee'd off for a feed to the cold water supply to the water heater via a flexi hose with a built in ball valve. I then carried on with the bit of copper and tee'd for the washing machine and finally a connection for the cold feed to the mixer tap on the kitchen sink.

I then fitted a flexi hose with a built in ball valve to the water heater and connected this to the hot feed for the mixer on the kitchen sink.
Prior to turning on the water heater I opened the main water supply and vented the water heater through the hot tap until all the air was omitted. I turned the power supply to water heater on turned on the hot tap on the sink, water came flowing through and it was ice cold. The green light on the heater shows there is power, but when hot water is demanded the green light goes off, but the red light which is supposed to indicate the water is being heated remains off also.
I fiddled about with the flow rate regulator on top of the heater but this made no difference.
I read the troubleshooting guide which directed me to the only problem it could have been being the water pressure was to low. So, I tested the water pressure and it is 4.5bar.

I rang manufacture told them I want my money back, they said they would test the unit if I returned it to them, I returned it, they tested it "apparently" and sent it back saying there was nothing wrong with the unit but the water pressure where it is being installed may be to high.

FFS I thought, so I dawdled off and bought a pressure relief valve, plumbed it in before the tee for the cold supply to the heater. Vented the unit, turned on the hot tap "cold water once again" so I started at 0 Bar and went all the way through at 1/4 bar increments to 4.5bar and at no time did the water become anything other than ice cold.

I rang manufacture and asked at what bar pressure did you test this unit? They replied between 1 and 3 bar with a flow rate of 1.9litres per minute. I tested the flow rate of my kitchen sink cold water supply and it was around 7.5litres per minute. BTW this is the Mother in Laws House that the heater is being installed in "Love Job".

I am at a loss, am I doing something wrong with the plumbing, I ask because I need to know before I send a scathing e-mail to them.

Thank you, ChirpyChippy

 

[Mikefromlondon]

You may have connected the cold water feed to the heater outlet and inlet of the heater to your kitchen sink, a distinct possibility! In other words connected wrongly or in reverse mode. ( even the most experienced and experts can often stumble)

 

[chirpychippy]

Thank you Mikefromlondon,

There are two ports, 1 has a blue ring on it, the other a red ring, I assume Blue is cold in and Red is hot out?

Stranger things have happened!!

 

[Mikefromlondon]

Yup you never know, like I said sometimes even the most experienced guy can stumble on things and not realise until he goes back to check.

Some instant boilers have so called load sharing priority switch, where the unit will not use power because another appliance is in use, this is to avoid over loading normal ring mains electrical circuits, but I had a quick look at the spec for this heater, it doesn't seem to have one, or I can't find any information if it has one, only your installation instructions would be able to clear that point.

 

[OwainDIYer]

There are two ports, 1 has a blue ring on it, the other a red ring, I assume Blue is cold in and Red is hot out?

Yebbut sometimes the people in the factory put the ring on the wrong thing.

 

[Mikefromlondon]

I gave this a little more thought, and realised that if your Green light is ON, presumably this is a neon light that draws very little current, and when you have a hot water demand, this Green light turns off and a RED heating neon SHOULD come on, but you said it doesn't, so that means your sparky has wired it incorrectly, (again this is based on a fact that you assumed it was faulty and so returned it to supplier/manufacturer, they tested it and found it OK) so you will need to get your electrician back and ask him to recheck his connections and wiring, because as soon as you place HW demand, it places a load on the power and perhaps due to a high resistance fault, the power collapses, all lights go out, so as if there is no power, so it seems there is an external fault which can be anything from MCB to cable connections, and final termination inside the heater.

Or perhaps it has been wired incorrectly with load sharing or priority load method, so it looks he will need to investigate.

have you not got any installation instructions, it should state if there is a load priority facility and it may have been connections incorrectly, and ask your sparky to recheck everything again.

In other words, your sparky may have connected it such that your heater thinks another high power appliance is in use, so it cuts itself out and the RED light also goes out along with your heating element and so you get ice cold water. So even though he wired it directly in 6mm cable, but there may be another switch or jumper or configuration that may be required, whatever to sense if another circuit somewhere else is in a priority mode and so cuts the power to your water heater, it may be a link or no link that should not be there. I don't have connection details, but all depending if it has "priority connection".

 

[chirpychippy]

Yes you may have a point with electrical connections, the instructions state it is fitted with a factory fitted bridge for single phase that has to be removed for 2 phase, this means sod all to me, although the factory fitted bridge may be in the factory connections of the terminal block. Whereas the sparky has put a bridge on the connections to the appliance!!!
The blue and red rings are printed on the unit

 

[Mikefromlondon]

Although I have not had to deal with any appliance with "Load Priority " concept, but I had heard of such terminology before, and I have been thinking how it can be implemented by any manufacturer, so yes you would need the priority load connected to "Live Out" terminal and your Live IN would be your incoming live feed fused and protected by an RCB. and like wise a Neutral IN and Neutral OUT.

(But my bet is either it has not been connected right, or there is wiring/power fault on this new cable, only your electrician can check this whilst you put the unit on hot water demand, and see if he still gets the 230v at its terminals.)

A priority load would function as when any load that needs priority over power sharing is connected to Live Out and Neutral Out, if a priority load (such as a kettle or a Microwaves Oven) was in use or being used, what this would do is prevent the water heater using all the 6Kw power for itself, or perhaps, none at all and divert all the power to a priority load.

This means the water heater would have connections where feed first connects in and then goes out to a priority outlet.

Heater would have a sensing circuit build in such that it would sense that a priority load is in use, the sensing part would be on the Heater control circuit board, and when it sees any voltage drop across this sensing resistor, it would know that a priority load is in use, and so stop letting power to its own heating element.

IF your mains power first connects to the heater, at L IN, and N IN, it would also powers a Green power on neon light, but then drops out when you try to make a Hot water demand, (Though it should remain on as far as I think, since it is still connected to live power) so it may already be sensing that a priority load is in use, so diverts power to a priority circuit, in doing so the green power on Neon or LED drops out and the RED light also stays off as a priority load is in being sensed or is in use. Or he simply connected it incorrectly whereby the sensing is on all the time.

However, you said your Electrician ran a dedicated 6mm cable to this heater, so i cannot think how your Green light goes out and Red light does not turn up, unless like I said it may have been wired incorrectly, or there is a high resistance wiring fault in the new cable he ran.

Further more I cannot find any installation guide on this heater, so I cannot confirm this. Point you mentioned about 2 phase connection or bridge, again I am not sure how that is as we in UK get a single or a 3 phase power.