Solar Panels and Unvented Cylinder anyone ?

[CB750K2]

My boiler came with the property and is no longer under warranty.

I have had several expensive visits from the manufacturers service team for the same low pressure problem and despite their Valiant efforts (geddit) in replacing the same parts several times I have had enough !

I am thinking of getting Solar panels and an unvented cylinder for the hot water and modern gas fires in the most used rooms, with electric heating in less used rooms.

Annual gas used 14000 kwh and electricity 4800kwh.

What do you all think of my idea and any recommendation of manufacturers ?

 

[muggles]

Sounds like an ultra expensive way of dealing with a relatively simple problem. Why not just get a new boiler if the present one can't be fixed? Or is there a leak on the system?

 

[ianmcd]

Sounds like you have a dirty system rather than losing pressure F75 fault code by any chance ?

 

[Gasguru]

You'd be surprised how little your hot water bill is compared with heating.

Me and Mrs GG get through £10 to £12 of gas for the hot water per month and we're not frugal. (I've got separate boilers for hot water and heating so it's easy to tell), sure a family will be a little more.
Solar panels and a new unvented (topped up with the electric element) will never pay for itself. Remember to add the costs of routine maintenance for both the cylinder and solar setup.
The more efficient the fire the more the service costs (it takes far longer).

Just sort out the leaky system...why are you using Vaillant?

 

[StephenStephen]

I do like that when our solar PV is producing more electricity than we use, then it heats our hot water, and that we don't use the gas boiler at all for about 6 months of the year, I just avoid thinking about the maths, and I really appreciate that money I'm going to not have to spend over the next 20 years is worth more to me than money I spent a couple of years ago.

 

[CB750K2]

Sounds like you have a dirty system rather than losing pressure F75 fault code by any chance ?

All four call outs in the last year have been F22 Low Pressure Code - none of the engineers mentioned a dirty system.

February 2019 F22 Low Pressure Code

Engineer found bottom of the case full of water.

Components replaced: Expansion vessel, Pressure relief valve, water pressure sensor, Automatic air vent, Connection tube (kit), Service kit

The next day failed again F22 Low Pressure Code !​

March 2019 F22 Low Pressure Code

Components replaced: Pressure relief valve again, Service cock

December 2019 F22 Low Pressure Code

Waited until after xmas before calling for an engineer.

Every couple of days I had to fill the system until the pressure was 1.5 bar

January 2020 F22 Low Pressure Code

Engineer found bottom of the case full of water again.

Components replaced: the diverter valve, Automatic air vent again

April 2020 F22 Low Pressure Code

I filled the system until the pressure was 1.5 bar

The next day an engineer called to check it over and said the pressure was still 1.5 bar and normal

 

[CB750K2]

Just sort out the leaky system...why are you using Vaillant?

Gasguru as you can see above I have tried to sort out the leaky system on my Valliant by calling out their engineers.

One can only take so much ! Hence in my despair thinking I don't want more of this perhaps a combination of electric, solar and gas fires might be simpler and less troublesome.

 

[CB750K2]

I do like that when our solar PV is producing more electricity than we use, then it heats our hot water, and that we don't use the gas boiler at all for about 6 months of the year, I just avoid thinking about the maths, and I really appreciate that money I'm going to not have to spend over the next 20 years is worth more to me than money I spent a couple of years ago.

I must say that I like your thinking with regards to hot water heating.

I have set the hot water temperature to 60c on my boiler and this suits us fine for showers and washing up .... what temperature does your solar panel deliver AND what temperature do you have your gas boiler set to for the winter ?

 

[lostinthelight]

If its any help, I have 10 x 315wh pv panels at 19° facing SW which are generating 936kwh per kw per annum
We switch the oil boiler off from March till October

 

[CB750K2]

If its any help, I have 10 x 315wh pv panels at 19° facing SW which are generating 936kwh per kw per annum
We switch the oil boiler off from March till October

It's certainly a great help and as I am south facing it shows me that I can do the same.

Do you have an unvented cylinder with an immersion heater just in case AND do you find the water temperature is hot enough for showers and washing up ?

 

[lostinthelight]

It's certainly a great help and as I am south facing it shows me that I can do the same.

Do you have an unvented cylinder with an immersion heater just in case AND do you find the water temperature is hot enough for showers and washing up ?

Yes I have an A rating unvented cylinder set to 60° so ,yes the water is very hot.
My heater is quite high in the tank which means the thermostat cuts the power sonot all the tank is at 60 .I have a secondary pump which mixes the contents and heating begins again filling the contents to 60

 

[StephenStephen]

I must say that I like your thinking with regards to hot water heating.

I have set the hot water temperature to 60c on my boiler and this suits us fine for showers and washing up .... what temperature does your solar panel deliver AND what temperature do you have your gas boiler set to for the winter ?

I don't have a thermometer on the tank, but in the summer the solar PV produces enough plenty enough excess electricity to heat water for showers, dishwasher, hot taps - it can often reach max temperature by late morning - I have the immersion heater thermostat set as high as it will go.
In the winter I set the gas water thermostat to between 55 and 60 ish, depending partly on the weather forecast, though it's only timed to be on for a short period (up to 40 mins at most) in the morning.

I was going to go for solar thermal, but they need more maintenance, are more likely to get gunked up and fail, and the various heating professionals we had round had all made the move to recommending solar PV for those reasons.

 

[lostinthelight]

My immersion thermostat is set to max which i thought was 60° but its not.
Ive just checked the temp at a tap with Fluke IR thermometer and its coming out at just under 70°...thats after two showers and washing up

 

[CB750K2]

Thank you StephenStephen, lostinthelight and Gasguru for your really useful information.

We have decided to go for the solar route and unvented cyclinder but it may be a while yet before I can make it happen.

In the meantime I will carry on with my research in to panels, unvented cylinders and if I have to stay with gas for cost reasons then a System Bolier ... any suggestions on that one gratefully received !

 

[muggles]

Thank you StephenStephen, lostinthelight and Gasguru for your really useful information.

We have decided to go for the solar route and unvented cyclinder but it may be a while yet before I can make it happen.

In the meantime I will carry on with my research in to panels, unvented cylinders and if I have to stay with gas for cost reasons then a System Bolier ... any suggestions on that one gratefully received !

Intergas ECO RF. 10 year warranty, can be integrated with solar thermal panels using the solar sensor accessory, very simple boiler with only 4 moving parts so very little to go wrong. Best boiler on the market IMHO