Solar Panels and Unvented Cylinder anyone ?

[Gasguru]

Immersion heater themostat temperature settings should be taken with a pinch of salt....it's common to find they are 10 degrees out even when they are brand new and have been "sealed" by the manufacture to indicate they have undergone testing.

A 13 year old Ecotec is riddled with design faults...leaking diverters, failing expansion vessels, poor quality pressure sensors, rubber hoses suceptable to debris buildup etc.

Most of those faults you've listed are due to lack of proper maintenance, system water quality (Vaillants need German unicorn tears) and poor boiler design.

AAVs and pressure sensors are almost a routine maintenance part changed every few years...

Fill to 1 bar max (unless there's an excessive height from boiler to top floor rads)...any more pressure and you'll give yourself more problems.

 

[JohnD]

I am thinking of getting Solar panels and an unvented cylinder for the hot water

Are you under the impression that solar panels generate a worthwhile amount of power outside the summer months?

They don't.

The cost is high and the return is inadequate.

 

[CB750K2]

Immersion heater themostat temperature settings should be taken with a pinch of salt....it's common to find they are 10 degrees out even when they are brand new and have been "sealed" by the manufacture to indicate they have undergone testing.

A 13 year old Ecotec is riddled with design faults...leaking diverters, failing expansion vessels, poor quality pressure sensors, rubber hoses suceptable to debris buildup etc.

Most of those faults you've listed are due to lack of proper maintenance, system water quality (Vaillants need German unicorn tears) and poor boiler design.

AAVs and pressure sensors are almost a routine maintenance part changed every few years...

Fill to 1 bar max (unless there's an excessive height from boiler to top floor rads)...any more pressure and you'll give yourself more problems.

Thanks Gasguru and I think you are right as there was no written evidence of maintenance when we moved in, so had it serviced and the graphite seal replaced.

We have a 3 bed semi, well insulated, just the two of us, only shower and like a winter temperature of 20.5c .... if I decide to stay with gas but have a system boiler instead of a combi, have you any thoughts on an Intergas or Viessman instead of the usual suspects ?

 

[CB750K2]

Are you under the impression that solar panels generate a worthwhile amount of power outside the summer months?

They don't.

The cost is high and the return is inadequate.

No I don't think that.

I want them for water heating only which I expect would be fine for the summer and according to others, would assist in the winter and if they didn't then the boiler or the immersion would kick in and keep the unvented cylinder water hot.

 

[oldbutnotdead]

The sums don't really work for solar pv at the moment. As far as I know FIT has either gone or been set at a very low level. The system mentioned earlier generating 963kwh per year- i'm paying 14. something p per kwh so your generation IF USED FOR POWER is worth about £145. If half the power is used for heating water and you have mains gas then that value drops to £100 ish per year.

 

[Gasguru]

The post has been hijacked by those with solar PV panels when the OP stated he was considering solar heated water.
Of course many of those with solar PV will be heavily subsidised by the public depending on the FIT at the time.
Solar PV is not maintenance free...give it enough years and something will fail...I have customers that have required a new inverter at significant cost, and it is still debatable whether the system will pay for itself (and these are customers that will hold onto the property for a decade or more).

Either way in this case the hot water energy demand is fairly insignificant compared to the heating energy usage. If you can save 50% of the water heating cost with solar (water) panels that will amount to less than £100 per year savings. No solar panel setup will ever recoup it's cost especially with the repairs and annual maintainence bill.
You'd be far better inproving the property insulation (25mm Celotex etc on the inner walls etc), draught proofing, TRVs, balancing the rads, quality LED lighting all round as the payback is rapid.

A system boiler contains a PRV, expansion vessel and pump. Personally I prefer a heat only boiler and keeping those components external to the boiler where I can specify (and if necessary upgrade ie. bigger vessel etc).

You'd be mad to touch Viessmann...they are just an experiment for the German manufacturer to produce the most complex boiler. No other manufacturer is on such a mission. Parts are extortionate, mail order only and few installers will want to repair it....too much hassle. Treat all boiler warranties with caution...especially with the future looking bleak, the small print in the T&Cs can void the policy for many reasons.

Intergas are popular on here due to the fan boys. All I will say is they are very niche market, and awareness in the trade is not out there. If you find an installer ask what will happen when they are away...who can you turn to for repairs etc. Of course with a cylinder you will have the immersion backup but consider a heating fault over Christmas or a bank holiday and your only installer is not around.

 

[JohnD]

the OP stated he was considering solar heated water.

at what point do you think he stated that?

 

[lostinthelight]

The sums don't really work for solar pv at the moment. As far as I know FIT has either gone or been set at a very low level. The system mentioned earlier generating 963kwh per year- i'm paying 14. something p per kwh so your generation IF USED FOR POWER is worth about £145. If half the power is used for heating water and you have mains gas then that value drops to £100 ish per year.

There is a new system in place now that pays a negotiated price per kWh for what is actually epxported, one has to have an export meter, and not paid on deemed export. Not sure if I made it confusing but that 963 kwh is times the the of Kwh of ones system .I generated 2900kwh so at 14ppKwh,thats £406 worth I didnt have to buy, plus I received £180.50 in Fit payment .

 

[bsr]

We have 4.2 kW of panels plus a solaredge inverter and an OSO tank with an iBoost for hot water. We don't use the boiler in summer.

I suggest getting a twin element tank. That way the solar will heat more water.

 

[lostinthelight]

We have 4.2 kW of panels plus a solaredge inverter and an OSO tank with an iBoost for hot water. We don't use the boiler in summer.

I suggest getting a twin element tank. That way the solar will heat more water.

Out of interest, which oso tank do you have

 

[bsr]

This is the label if it helps.

 

[lostinthelight]

Thanks for that, have a look at my post and could you please tell me if your controls are the same and how far from the cyl is the iboost.Oh, is it an iboost or iboost+

 

[Gasguru]

"I am thinking of getting Solar panels and an unvented cylinder for the hot water"

Normally taken to mean a water based solar system.

 

[StephenStephen]

Are you under the impression that solar panels generate a worthwhile amount of power outside the summer months?

They don't.

The cost is high and the return is inadequate.

You're making assumptions here about what "worthwhile" means - so this is a gentle reminder that it means different things to different folk.

 

[flameport]

From the information given, the OP needs a new boiler.
Spending 10x more on an entirely new system with solar panels, unvented cylinder, gas fires, electric heaters and whatever else they had ideas about is a colossal waste of money.