Electrics provision for system boiler and megaflow with immersion heater
- Thread starter Jupiter01
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It will depend on the layout, where the various items are, pump, Valves, wiring centre etc
if you have an S or Y plan, all sorts.
Your plumber or electrician can only advise on site. To get an idea, there are sample wiring diagrams in the Megaflo installation manual. Here you are.
Type of cable? Multi core 1mm. How many cores depends on the circuit.
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Which lies are you expecting him to tell?
The ones on the EIC about him having designed and installed this?
The one to Building Control about him having been responsible for all of it?
I'm sitting here totally unable to understand what kind of thought processes can possibly be going on inside the head of a man who finds he has to ask so many questions and yet does not regard his ignorance as a reason why he is not competent to carry out electrical design work.
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Ask your electrician, which is presumably yourself?
Sorry for the incessant questions. I do have a "proper" electrician on board who has advised me and is inspecting the cables I have laid but he is away at the moment and I wanted to check that I am on the straight and narrow. He will be reviewing the installation (prior to boarding and plastering) and commissioning it.
I ask about the thermostat cable as he suggested wireless thermostats but I thought it would be better to have a wired system now that I have an opportunity.
I ask about the thermostat cable as he suggested wireless thermostats but I thought it would be better to have a wired system now that I have an opportunity.
You are right to go for wired thermostats....I'm sure that's something you and BAS can both agree on.....
If you have the stats, or know which you want, get the manuals out/download them, and work out the cabling requirements from there.
Generally a stat needs a supply, and a switch wire (switches the incoming line back to boiler controls to fire the boiler), so 3 core and earth will do the job, but you need to check what your stats/boiler controller specifically require. You might need to wire both sides of the switch back if you have two zones, dunno, not familiar with zoned heating controls.
The advantage of wireless stats is that you can move them around to the most suitable location, should you want/need to change it later.
The disadvantage is that they are, well, wireless - and wireless stuff can be flaky depending on the location/environment. Plus you have to feed them with new batteries from time to time.
Think carefully about all of this stuff, if you are starting from scratch. There are some systems that allow you to control heating and hot water from a smartphone. For example: Hive, Heatmiser, etc
The disadvantage is that they are, well, wireless - and wireless stuff can be flaky depending on the location/environment. Plus you have to feed them with new batteries from time to time.
Think carefully about all of this stuff, if you are starting from scratch. There are some systems that allow you to control heating and hot water from a smartphone. For example: Hive, Heatmiser, etc
They always are, aren't they.
Reviewing and commissioning could indeed be inspection and testing.
But...
I being the person responsible for the design, construction, inspection & testing of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, construction, inspection & testing hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2015 except for the departures, if any, detailed as follows:
If he doesn't do the design & construction, how can you expect him to sign to say he did?
And...
I looked at a Salus IT500 wireless programmable stat for operating my combi boiler, but being a tight-fisted Yorkshireman, couldn't justify the additional cost for the maybe once or twice a year I might like to switch the heating on whilst travelling home, preferring to arrive back to a cold house.....each to their own of course.
I went for a wireless programmable stat from Plumbcenter for £51, and it's been reliable so far. As opposed to the Horstmann one, which was less than reliable.
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I looked at my brother-in-laws Mega flow system and that was by no means a simple system. It had two immersion heaters and around three hot coils and twin tanks the whole idea of the system was to bring together all the power which could be used for heating.
So feeding in we had solar panels, wood burning fire, emergency LPG gas boiler and mains power. Coming out there was domestic hot water, central heating, and a heat sink radiator to remove excess energy if there was too much. It was all installed from new and there when he bought the house.
I felt it should have included an UPS system to ensure pumps ran to remove heat from back boiler even if there was a power cut, but it seems this was never installed. Solar panels both direct water and electric it seems to comply with government grants and maximum sizes, it would have worked better all electric.
There were temperature senders every where including a HMI (Human machine interface) next to the wood burner telling him how much heat was stored. Clearly if already at 90% then did not want to run the wood burner.
I would love to say I had designed his system, but no I just looked at it and wondered is it really worth that much money to reduce energy bills? It seems the immersion heater was a special, in real terms a three phase model so he could select 1, 2, or 3kW or at least the system selected it depending how much power the solar panels were making.
OK yours may be a mush simpler system, but you have at least two sources of power and as with his nothing to stop you using off peak power and heating the house by electric. He could enter fuel prices and the system would select the cheapest.
To my mind having an immersion heating a water store for domestic water only is very different to using it to heat the house. The times the heater runs for would be very different and it also may be better to be indirect. With a heat store you can either use the water heated direct or use a heat exchanger or hot coil to heat the cold water mains input as required the latter better in hard water areas.
With systems the idea is design maybe six times, but fit only once. So it is design which is super important. Until you have laid out exactly what the system is intended to do than really can't help. The mega flow heat exchanger is an expensive bit of kit, clearly not a simple cistern and header tank. I just can't see how when the materials likely cost £16k you would DIY the electrics?
So feeding in we had solar panels, wood burning fire, emergency LPG gas boiler and mains power. Coming out there was domestic hot water, central heating, and a heat sink radiator to remove excess energy if there was too much. It was all installed from new and there when he bought the house.
I felt it should have included an UPS system to ensure pumps ran to remove heat from back boiler even if there was a power cut, but it seems this was never installed. Solar panels both direct water and electric it seems to comply with government grants and maximum sizes, it would have worked better all electric.
There were temperature senders every where including a HMI (Human machine interface) next to the wood burner telling him how much heat was stored. Clearly if already at 90% then did not want to run the wood burner.
I would love to say I had designed his system, but no I just looked at it and wondered is it really worth that much money to reduce energy bills? It seems the immersion heater was a special, in real terms a three phase model so he could select 1, 2, or 3kW or at least the system selected it depending how much power the solar panels were making.
OK yours may be a mush simpler system, but you have at least two sources of power and as with his nothing to stop you using off peak power and heating the house by electric. He could enter fuel prices and the system would select the cheapest.
To my mind having an immersion heating a water store for domestic water only is very different to using it to heat the house. The times the heater runs for would be very different and it also may be better to be indirect. With a heat store you can either use the water heated direct or use a heat exchanger or hot coil to heat the cold water mains input as required the latter better in hard water areas.
With systems the idea is design maybe six times, but fit only once. So it is design which is super important. Until you have laid out exactly what the system is intended to do than really can't help. The mega flow heat exchanger is an expensive bit of kit, clearly not a simple cistern and header tank. I just can't see how when the materials likely cost £16k you would DIY the electrics?
Get real Eric. It's nothing like that complicated, or that expensive.
It sounds like he's got an indirect Megaflo system (note spelling). Water heated from boiler with an immersion purely as a standby.
It's probably an S or Y plan? Not sure how or why he needs two zones? We don't know if it's radiators or wet underfloor system. But £16k, never.
It sounds like he's got an indirect Megaflo system (note spelling). Water heated from boiler with an immersion purely as a standby.
It's probably an S or Y plan? Not sure how or why he needs two zones? We don't know if it's radiators or wet underfloor system. But £16k, never.
Coming late to this but seeing as you've already laid the two 2.5s, what I would do is this - change your ring circuit design to two radial circuits both on 16A MCBs (assuming you have another free way in the CU), one for the immersion via a 20A switch and the other for your double socket plus the FCU fused at 3A feeding the boiler circuitry.
N.B. Some boiler MIs state an unswitched 13A socket rather than an FCU as the preferred connection method.
N.B. Some boiler MIs state an unswitched 13A socket rather than an FCU as the preferred connection method.
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£16k!!!!
I appreciate the point you are making but I now have three quotes and all of them added together still don't come to that figure. That includes parts and labour on each quote!
Thanks for all the helpful contributions guys. I appreciate the constructive feedback.
I appreciate the point you are making but I now have three quotes and all of them added together still don't come to that figure. That includes parts and labour on each quote!
Thanks for all the helpful contributions guys. I appreciate the constructive feedback.
Which boilers say that? I have never, ever seen that. The usual stipulation is a double pole switch with an isolation gap of 3mm minimum.
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