Hot water thermistor

[Gast]

Installing a new system in a renovation project. Having a valiant boiler and cylinder (and 12 way manifolds). The plumbers are happy with 230v switched inputs for both heating demand and hot water demand, but suggested I hook up to the 2.7k thermistor for reading the current hot water temperature. Any ideas on this? I’ve found a small circuit on eBay for a 10k thermistor to 0-10v input, but not sure if can adapt it, or if any other options?

[duncan]

ive used one of the common 1-wire waterproof sensors pushed in to the temperature sensor tube of the cylinder - its direct readout of temperature unlike your thermistor solution

[Gast]

Will have to have a look, do you have an eBay or other link for one. Wonder how easy it is to replace on the cylinder, on the plus point I’ve got 1-wire in for temperature sensors. First 4 lights connected.

[duncan]

ive attached the pdf for the cyclinders i used - item 5 on the diagram on page 2 shows the open empty thermostat tube/pocket - other cylinders will have something similar

https://www.ebay.co.uk/itm/DS18B20-18B20-1-WIRE-Digital-Thermometer-in-waterproof-casing-Amazing-Value-UK/190840198748?hash=item2c6ef6565c:g:x-EAAOxy3HJTJCc4

there are loads to choose from

my cyclinders have an external open tube into which a thermistor can be placed - just push in the metal sensor, i used a piece of foam jammed into the hole to keep it in place

[Gast]

Thanks, got a pocket on the tank, hopefully get that in next week (along with all the valves on the manifold and the switched live demand lines to connect up).