[Solved] Hot water issue, never seen this before: Grant Heat Pump and Cylinder
This is so weird. Cylinder is heating up fine. Temp says 53 right now. But when I run the cold tap it’s hot only for a short period and then cools down very quickly so I have lukewarm water at best.
Anyone ever had this?
Baffled of Ayrshire
Any updates on your situation?
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
Follow our sustainability journey at My Home Farm: https://myhomefarm.co.uk
Posted by: @editorAny updates on your situation?
not yet. It did resolve itself for a while yesterday but is back to the same issue now.
We have had water pressure issues in the area due to power outages affecting pumping stations but I just don’t know. Our plumber was too far away yesterday to come but hopefully will come today.
do you have a blending valve (TMV) on your hot water supply from the cylinder?
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
Are you sure you've describe it the right way round? Your description says the cold tap runs hot then lukewarm? Did you mean the hot tap? If so then either there's not enough hot water in the cylinder or something is blending in cold when it shouldn't be, such as a TMV.
If it IS the way you described it please confirm.
My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs
@hughf I would expect so. It’s a Grant pre-plumbed cylinder and I do suspect the issue is with blending.
I’m waiting for plumber to take a look now.
@iancalderbank yes, that’s right Ian. I mistyped in my opening post. It is the hot tap. Runs, gets hot and then quickly becomes lukewarm when I know for a fact there is plenty of hot water in the tank.
Posted by: @marvinator80@iancalderbank yes, that’s right Ian. I mistyped in my opening post. It is the hot tap. Runs, gets hot and then quickly becomes lukewarm when I know for a fact there is plenty of hot water in the tank.
ok no worries . in which case I concur with yourself and hughf, blending valve is the first place I'd check. you should be able to feel the temperature of its 3 ports change over time as you run the water.
My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs
Thanks everyone. I’m not sure what the blending valve looks like on the grant set up. I guess a plumber will know. 😬😬😬
@marvinator80 its not a grant specific component. Find the hot water output pipe coming out the cylinder and follow it.
something like this
My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs
@iancalderbank I can’t see anything like that. This is the bit where the water seems to mix, but I’m not sure. I guess if that’s faulty it will need replaced. Trying to gently hurry up my plumber.
@marvinator80 no thats one of these
stops your cylinder blowing up if its gets too hot or high pressure due to some control error.
one of the pipes will go via a short route to outside. "emergency dump pipe"
My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs
- 24 Forums
- 1,413 Topics
- 29.7 K Posts
- 48 Online
- 1,199 Members
Join Us!
Latest Posts
-
RE: Gas Combi to ASHP - Making sense of survey results and proposal.
Also, to satisfy the inner control freak you could ensu...
By ajn9000 , 2 hours ago
-
RE: Fossil Fuel Fired Heating v Heat Pump?
Another aspect was the DHW heating; the coal fire in th...
By Toodles , 3 hours ago
-
In an ideal world a heat pump unit would contain two co...
By Derek M , 16 hours ago
-
RE: ASHP Advice: High Temperature vs. Low Temperature Heat Pump For Microbore
@jamespa I fully agree with James that a HT heat pump...
By Derek M , 18 hours ago
-
RE: Installing your own ASHP - DIY
@tomasmcguinness Have you been able to perform any sani...
By IanMK13 , 22 hours ago
-
RE: Viessmann Vitocal 250-A in the UK
For reference, I have a 10 kWh Viessmann 151-A installe...
By GC61 , 24 hours ago
-
RE: Vaillant Arotherm Settings for New Installation
@drew-pa Ah thanks. Good to know I dont have a misconce...
By bontwoody , 1 day ago
-
RE: Aira Heat Pump: Stylish Scandinavian Heating
On the whole marketing claims vs reality on performance...
By GunboatDiplomat , 1 day ago
-
RE: Microbore Central Heating Plumbing, will it be a barrier / pain?
@mattc All the existing (designed for T50) radiators ar...
By IanMK13 , 2 days ago
-
The temporary fix has reconnected about 60% of users, a...
By Abernyte , 2 days ago
-
RE: What is Wrong with our Heat Pump Installation?
Having to run the heat pump during the summer for DHW s...
By Toodles , 2 days ago
-
Issues with Vaillant connectivity via the MyCONNECT gateway
I'm sensing a variety of issues with Vaillant connectiv...
By dr_dongle , 2 days ago
-
Interesting heat pumps installations
Thought it would be cool to share photos of interesting...
By Mars , 2 days ago
-
RE: Say hello and introduce yourself
@Toodles That's very interesting to hear, thanks. I ha...
By dr_dongle , 2 days ago
-
RE: Massive Electricity Cost for Running My Air Source Heat Pump
@allyfish In fairness installer has replied stra...
By Holts , 2 days ago
-
-
RE: Are Solar Diverters Necessary for Homes with ASHPs and Solar PV?
@zzxap19 that's a fair point. With the eddi, is it poss...
By Mars , 3 days ago
-
RE: Delivering a smart and secure electricity system: government consultation
"I don't think I'll need to refer to past iterations of...
By eggnchips , 3 days ago
-
RE: Error on Immersun – Error 8 Load Short Circuit
@julesmp8 fingers crossed. I have to say our Immersu...
By Mars , 4 days ago
-
Latest Topics
-
Interesting heat pumps installations
By Mars 2 days ago
-
What is Wrong with our Heat Pump Installation?
By Mars 3 days ago
-
Fossil Fuel Fired Heating v Heat Pump?
By Toodles 3 days ago
-
Viessmann Vitocal 250-A in the UK
By treehugger 5 days ago
-
By HUBB84 7 days ago
-
By jswhite 1 week ago