Or: Why not to believe that an engineer is always right.
Since we moved in, the heating system hasn’t worked. Literally. First of all I couldn’t get the boiler to stay lit, despite following all the instructions. Then, it started blowing the 3amp system fuse, rendering the system utterly kaput.
So, better safe than sorry, I called in an engineer.
Cost: £80.
He got it lit onto the pilot light (It’s a 1997 vintage Baxi Bermuda backboiler with the horrible firefront). Then he went to poke at the “non gas” bits. I accompanied him.
He removed the cover of the wiring center. Spent 15 minutes tryingt to get his test meters to work (poor maintenance there, tut). Then he started poking bits. I heard “Oh shit. OH shit. OH SHIT” as he poked various wires.
“Your pump’s gone.”. Well, *I* had narrowed it down to either pump, 3 port valve or control failure. So he disconnects the pump..”oh no, it’s fine”. Yes, I knew that. I HAD got it running boilerless for 2 minutes at one point.
Opinion then revised to “It’s your 3 port valve”. Hmm. Possible – it sounds like it’s on it’s last legs anyway..groans and pings like a mad thing.
“I’ll call you back next week (this was a Friday)..you need a 3 port valve, a universal thermocouple, and a service.”
Off he toddles, £80 better off.
The next week, no call. So I thought “sod it.”. The last thing that happened to the system before it popped was I knocked the thermostat on the wall. I don’t LIKE that one anyway, and had bought a unit to replace it.
Power off, multimeter out. Rubber gloves on (safety first, haha). Thermostat opened up, 3 wires off. 2 screws out, thermostat off the wall.
Power the system up…fuse doesn’t blow. set hot water to “on”..valve chugs over to port B, pumps hums and spins up..boiler fires up. BINGO.
It’s the poxy thermostat. Power off again. Look at wiring – there’s a red, yellow and blue..connected to terminals 1, 3 and 4 If I recall. That’d be “Live” “Neutral” and “Switch Live” then.
I already said I didn’t like the thermostat we had..it’s one of the basic dial types, a Honeywell T6360..ours was a “C” variant, that has a supplemetary “on/off” switch. No intelligence there. BORING.
I’d bought in advance one of these babies:
-01.JPG "Digistat")
A Drayton Controls Digistat 3+. “Set and forget”. You can specify 6 times of each day, and a temperature you want the house to be BY that time..it does the rest and adapts to the house, the temperatures, the boiler heat generation etc. Also has a holiday function to mind the house at a lower level but get it warm for your return and lots more. Cost was £25 from eBay.
This was a 2 wire thermostat that runs off batteries. So..the Neutral wire I was advised is now not needed. OK, I heat-shrinked it off and made it safe. The remaining 2 wires ran to the digistat back panel relay.
Programmed the Digistat, clipped it onto the backplate. System power on again, all good. Water on, that works, boiler starts. Override the digistat temperature program and ask for heating as a test..”click, whirrwhirrwhirr”, hum, WHOOMF”…followed by a shout from Jem – “Boilers lit!”
Yee-HAH.
I was going to replace the programmer..a Honeywell ST699 digital 24 hour job, as that is also inflexible for us. However, the Digistat has rendered that unnecessary. The ST699 is now purely a relay for the digistat, and a controller for the hot water demand. Hence, heating is on “Constant”, water is set to heat from 5pm-6pm for Izzy’s bath. Apart from that we don’t need any (Electric shower, dishwasher etc)
For a materials cost of £20, we now have a fully intelligent functional heating and hot water system.
The engineer, when called said “Oh. Yeah. I’ll be back out in half an hour..it’ll be another £80.”. I said forget it. Plus the valve he wanted to replace is an £80-90 part.
Got a guy coming tomorrow who’ll charge a flat £55 to service the bermuda and firefront, that’ll do nicely. If the thermocouple needs replacing (possible, would explain the difficulty lighting it), that’s fine. They’re cheap.
I shal have this unit service yearly for safety, and although it’s old and inefficient I expect it to be a lot cheaper to run than the cottage boiler was..that was routinely £550 bills to maintain a temperature of 15 degrees..the house can hold a steady 21-23 degrees even with the boiler broken down. Impressive! It rarely needs to cut the heating in.