Xerxes991

Thanks for that. Yes, I did try it. But I couldn't find anything that seemed right - most were for air or hydraulic fluid duties. I checked the John Guest Speedfit site, but they don't do anything in 8mm for hot water or central heating systems. They do something in acetal for food & drink applications such as water dispensers. So it looks like I'll need to go old school with brass compression fittings...:-(

Hello I'm having to connect old 8mm copper radiator piping to new 10mm plastic piping. Simple, you might think. But I'm struggling to find 10mm to 8mm push fit reducers. I only seem to be able to find brass compression fittings. Any suggestions for types of fitting and possible suppliers please? Thanks.

Thanks Billt That’s very helpful. My conventional (therefore quite large) vented cylinder is reheated periodically, rather than on demand, so the small hysteresis is not a problem for me. I think I’ll give it a go. Just have to make sure the sensors are in intimate contact with the copper wall, and well buried in insulation. Steve W

Thanks for the manual link. It’s not clear what happens if it does not achieve 60 for the full hour. Does it simply stay on demand at that temp until the condition is met, I wonder? The manual also goes on to say the timing/frequency of the “boost” can be adjusted, or totally disabled. If necessary I could manage without the boost perhaps. I’ve survived without Legionella protection for 70 years so it’s probably one of my less important health risks! The device is £25 and seems a bargain. I’ll call their tech people (?) and see if they do a version for vented cylinder, and what they suggest about attaching the sensors. Many thanks for your comments - much appreciated.

Good point. I would plan only to use it as a simple thermostat, with all the ON/OFF cycles set in my new Hive thermostat. So I could set the Legionella cycle to be time constrained within one of the ON periods, when all other zones are off. Any suggestion on how to ensure best thermal contact between the sensors and the copper surface of the cylinder?

That’s amazing. And I do have a Raspberry Pi, but I think my airing cupboard might not be the best place for a project like that. I’m leaning towards the ESI device, which is designed for unvented cylinder with pockets. But I’m sure I could just embed the sensors, in contact with my cylinder wall. Does that sound reasonable? ESI - Energy Saving Innovation Controls ESCTDEB ESI Controls Electronic Dual Cylinder Thermostat, White https://amzn.eu/d/5YI7znx

Not bad (for a mechanical engineer). Have you got a home brew suggestion? Sounds interesting.

Thanks Peter. I was hoping to spend rather less than that 😟. I don’t need the RF functionality since the TS wiring is already at the cylinder, and I can add a permanent live feed fairly easily. So I was hoping for a “simple” switch with local digital readout.

My ancient clamp-on cylinder stat needs replacing. I would like one that allows me to read the current tank temperature as well as set the target temperature. Ideally, it would let me do that via smartphone app, but a local display would be ok. That should all be easy in 2022, you would think. But I’m struggling to find any, other than ones designed to fit in the pocket of an unvented cylinder. Any suggestions, please? Thanks, Steve W

JohnMo, thanks for that, but... Aaaagghh! Complications. My plumber has just got back to me to say that conventional boilers are getting difficult to get hold of. And so he proposes installing a Combi Boiler (35kW), BUT only using the indirect part of the boiler to feed the two CH zones (16 rads in total) and the two HW cylinders. Does that sound feasible? I suppose I could set it up as "Always On", and just use my controls and thermostats. At least it would give me a new pump. You could argue that it leaves me with some future flexibility if I wanted to re-configure the house. But on the other hand, is it giving me more complexity and more things to go wrong? I don't yet know what the cost implications are, but perhaps they are not significant.

Many thanks for quick (and comforting) reply. The Glow-Worm is floor mounted in corner of utility room, under work surface, with cabinet above. I assume replacement boiler would be wall mounted, so cabinet would go, but I should be able to fit an under worktop cupboard to compensate. There is enough width, and it is adjacent to sink, so condensate piping should be fine. I'm hoping it will be a relatively minimalist job - but who am I kidding? 🙂 Anyone got suggestions for 25-30kW boiler? I see that the lowest rating Worcester Bosch Greenstar 8000 is 30kW. On a conventional system, does it matter too much if the boiler is a little overpowered?

I have a 30 year old Glow-Worm Hideaway 70B balanced flue gas boiler, which I assume has pretty low efficiency compared with a modern boiler. It may also have a fairly limited residual life. My gravity system is a bit unusual as I have an old single storey house which is rather long, with a bathroom at each end. Because of that, it has a HW cylinder at each end of the house and the house has two CH zones. So I have a total of four circuits, each with a two port valve, for the two HW cylinders and the two CH zones. The two Room Stats are programmable WiFi, which I recently installed, and which work very well. The two HW circuits are still controlled by the original simple timers. My "simple" plan is just to replace the Glow-Worm with a new conventional condensing boiler in the same location. I don't really feel a need to remove the HW cylinders since I have a bath in one of the bathrooms and the pipe runs to it are quite long. So a Combi boiler doesn't feel right. Also, the HW cylinders are in airing cupboards, so the heat loss from them is not entirely wasted. But I feel I ought to consider other options...any thoughts from anyone? Many thanks.

Retired, living near Darlington. Hope to get a little guidance on my home improvement challenges. I look forward to learning from you all.